La ansiedad es un proceso afectivo que recibió mucha atención en Psicología del Deporte, ya que por sus características es un ámbito fructífero para estudiar este proceso. En Argentina no se hallaron instrumentos adaptados que evalúen este constructo en ámbitos deportivos. El objetivo del estudio realizado fue adaptar el Revised Competitive State Anxiety Inventory-2 (Cox, Martens & Russell, 2003) a una población de deportistas argentinos. Siguiendo la teoría multidimensional de la ansiedad de Martens (1974), este inventario posee 17 ítems distribuidos en tres factores: Ansiedad Somática (AS), Ansiedad Cognitiva (AC) y Autoconfianza (ACF). Se realizaron tres estudios instrumentales y uno de diferencias entre grupos para analizar si existen diferencias en los niveles de ansiedad en función del sexo, deporte y modalidad deportiva (individual - grupal). El estudio de entrevistas cognitivas posibilitó la ampliación del número de ítems por factor. Así, se analizó la estructura interna de 22 ítems mediante un análisis factorial confirmatorio. El inventario replicó la estructura factorial original con 8 ítems para ACF,7 para AS y 6 para AC. La confiabilidad presentó valores moderados a altos (de ρ = .84 a .96). Finalmente, se hallaron diferencias en función del sexo, deporte y modalidad deportiva en los niveles de AC y AS, mientras que las diferencias en ACF sólo se hallaron en función del sexo. El inventario posee adecuadas propiedades psicométricas y por lo tanto, es apropiado para la evaluación de la ansiedad estado competitiva en población deportiva argentina. Se espera que futuros estudios analicen las diferencias en los niveles de ansiedad considerando otros deportes, controlen el efecto de la edad y analicen la validez convergente del inventario. Participating and/or competing in sports have certain characteristics that make the field of sports a productive one for the study of affective processes such as anxiety. It makes sense, then, that anxiety is a process that has received much attention in Sports Psychology since its beginnings as a discipline. Despite this, in Argentina there are currently no instruments to assess this construct in relation to sports. The aim of the present study was to adapt the Revised Competitive State Anxiety Inventory (CSAI-2R - Cox, Martens, & Russell, 2003) for use with Argentinean athletes. The CSAI-2R is composed of 17 items measuring three constructs, following Martens multidimensional anxiety theory (1974): Somatic Anxiety (SA), Cognitive Anxiety (CA), and Self-Confidence (SC). Three instrumental studies were carried out: cognitive interviews, a rating study and internal structure, and one of internal consistency. Finally, a group differences study was conducted. The cognitive interviews consisted in evaluating question comprehension by 10 athletes between the ages of 18 and 27 using a verbal probing technique. For the rating study, two experts in Sports Psychology and Psychometry judged the inventory's items in terms of their quality, as well as their congruence to the factors of interest. Lastly, for the studies of internal consistency and structure and of group differences study, the CSAI-2R was administered to 357 athletes 15 to 45 minutes prior to competing. The sample was made up of 162 females athletes and 195 males athletes between the ages of 11 and 47 (M = 21.83, SD = 5.90) overall averaging 9.18 years practicing their respective sports and all having competed at a regional to international level at least once a year (M = 2.94, SD = 2.38). The cognitive interviews helped clarify items, as well as add new ones (13 items) to be tested in subsequent studies. The rating study revealed complete agreement between the judges as regards congruence (k = 1.00; p < .05), although 8 items had to be eliminated due to poor quality (< 3). Thus, the final version the CSAI-2R replicated the original factorial structure with a total of 21 items. One item was eliminated and two had to be replaced because their factorial weight was below the established threshold of .40. Confirmatory Factor Analysis showed adequate indexes (CFI.954, TLI .948 RMSEA .062, 90% CI .055 .070, WRMR 1.199). Internal consistency of the inventory showed moderate to high composite reliability values, (from .84 to .90). Overall, the composite reliability for CSAI-2R was .96. Regarding sex differences, t tests yielded statistical differences in the levels of CA (Mmen = 11.32, Mwomen = 10.12, t(347) = 3.24, p < .05), SA (Mmen = 9.61, Mwomen = 10.81, t(347) = 3.81; p < .05), and SC (Mmen = 26.01, Mwomen = 24.55,t(347) = -2.87, p < .05). Also, sport modalities (group-individual) showed differences in SA (Mindividual = 10.89, Mgroup = 9.87, t (346) = 2.83, p < .05, d = .32) and AC (Mindividual = 9.94, Mgrupal = 10.94, t (347) = -2.47, p < .05, d = -.29). Finally, ANOVA showed differences in SA, F(3,345) = 4.39, p < .05 and CA, F(3, 345) = 3.31, p < .05 between sport type; Tukey post hoc tests showed that martial arts practitioners had higher levels of SA than soccer and hockey practitioners and lower levels of CA than field hockey practitioners. The CSAI-2R demonstrates good psychometric properties and, therefore, is an adequate instrument to assess competitive state-anxiety in Argentinian athletes. However, new instrumental studies are needed in order to check convergent validity and include new sports. Also, socio-demographic variables like age need to be taken into account in group differences studies.