Objective Evaluate the palmar, lumbar and lower members preehension strength in bearers of mental deficiency with and without Down`s Syndrome. Material and Methods: Descriptive and inferential field study expo-factus. The sample was constituted by 110 individuals of the masculine gender with ages between 20 and 40 years old distributed in three groups: 40 formed the controls group (GC), for not presenting mental deficiency, 30 formed the group bearing metal’s deficiency with Down`s Syndrome (GSD) and 40 the formed the group bearing metal’s deficiency without the referred syndrome (GDM). The data were analyzed being used the program SPSS for Windows® version 12.0. Firstly, the data were clustered so that there was a general scenery of the variables contrasting the groups (GC, GSD and GDM). The descriptive analysis of the quantitative data surfaced as a location measure (central tendency) – the Average - and as data’s dispersion – the Average Deviation. ANOVA was used, comparing the matched samples to establish if there was significance difference among the groups, where the level of significance established was 0,05. Results: There is palmar’s preehension strength prevalence in function for the right hand in relation to the left one in each and every of the studied groups; the muscular hipotony characteristic of the Down’s population generates significant and preoccupying deficit of the strength in this population; there is a low correlation between palmar’s preehension and lumbar strength, and also between palmar’s preehension strength and the lower limbs. Conclusion: It`s important to stimulate the practice of physical activity in that population, seeking life quality improvement and the consequential daily life activities (AVD's) performance, also offering a chance for social independence by being economically rewarded for whatever they are capable to produce. It is then placed as challenge for the public health system to include and take care of a growing population. Measures should be taken to guarantee the inclusion as well as the permanence of this population in the job market and to make conscious the professionals that assist it regarding the importance in guaranteeing the functional integrity of the muscle-skeletal system.