Purpose/objectives: The purpose was to describe the number, demographic characteristics, work patterns, exit rates, and work perceptions of nurses in Ontario, Canada, in 4 specialty classifications: advanced practice nurse (APN)-clinical nurse specialist (CNS), APN-other, primary healthcare nurse practitioner [RN(extended class [EC])], and registered nurse (RN) with specialty certification. The objectives were to (1) describe how many qualified nurses are available by specialty class; (2) create a demographic profile of specialist nurses; (3) determine the proportions of specialist and nonspecialist nurses who leave (a) direct patient care and (b) nursing practice annually; (4) determine whether specialist and nonspecialist nurses differ in their self-ratings of work environment, job satisfaction, and intention to remain in nursing. Employment patterns refer to nurses' employment status (eg, full-time, part-time, casual), work duration (ie, length of employment in nurses and in current role), and work transitions (ie, movement in and out of the nursing workforce, and movement out of current role)., Design: A longitudinal analysis of the Ontario nurses' registration database from 2005 to 2010 and a survey of specialist nurses in Canada was conducted., Setting: The setting was Canada., Sample: The database sample consisted of 3 specialist groups, consisting of RN(EC), CNS, and APN-other, as well as 1 nonspecialist RN staff nurse group. The survey sample involved 359 nurses who were classified into groups based on self-reported job title and RN specialty-certification status., Methods: Data sources included College of Nurses of Ontario registration database and survey data. The study measures were the Nursing Work Index, a 4-item measure of job satisfaction, and 1-item measure of intent to leave current job. Nurses registered with the College of Nurses of Ontario were tracked over the study period to identify changes in their employment status with comparisons made between nurses employed in specialist roles and those registered as general staff nurses. Analysis involved descriptive summaries, mean comparisons with independent-samples t test, and χ(2) tests for categorical data., Results: Exit rates from direct practice were highest for APN-other (7.6%) and CNS (6.2%) and lowest for RN(EC) (1.0%) and staff nurses (1.2%). χ(2) Tests indicated yearly exit rates of both APN-other and CNS nurse groups were significantly higher than those of staff nurses in all years evaluated (α = .025). Every specialist employment group scored significantly higher than staff nurses on measures of work environment and satisfaction outcomes., Conclusions: We provided a description of specialist nurses in Ontario and examined the relationship between specialization and employment patterns of nurses to inform nurse retention strategies in the future. Employment in specialist nursing positions is significantly associated with differences in transitions or exits from nursing among the specialist and nonspecialist groups. Registered nurses (EC) displayed improved retention characteristics compared with staff nurses. Advanced practice nurse-other and APN-CNS exit rates from nursing practice in Ontario were comparable to staff nurses, but exit rates from direct clinical practice roles were higher than those of staff nurses., Implications: Targeted strategies are required to retain CNS and APN-other in direct clinical practice roles.