Introduction: Nursing practice takes place in a context of ongoing advances in research and technology hence, basic nursing education alone is no longer sufficient for a lifetime nursing career. However, participation in Continuing Professional Development (CPD) in many countries in Africa remains low. The objective of the study was to investigate factors influencing nurses’ participation in CPD in Western Kenya. Methodology: This was a descriptive cross- sectional study design of 235 stratified and randomly selected nurses and four CPD Coordinators from four County Hospitals in Western Kenya. The Key informants and the respondents for Focus Group Discussions were selected purposively. Data for this research was collected using a semi-structured questionnaire, interview schedules and Focus Group Discussion guide. Data analysis was done using statistical package for social sciences (SPSS V. 20). Statistical techniques including t-test, Chi-square and multiple logistic regression model were employed in the analysis. Qualitative data was analyzed thematically. Results: Majority of the nurses 195 (84%) participate in CPD. The five major factors that influence nurses to participate in CPD were; to obtain additional qualification, improve their Curriculum Vitae (CV), to be updated with new developments, career progression, networking with other nursing colleagues and to be prepared for mentoring new nurses and students (mean<3). All the four Coordinators considered appraisal, promotion, earn CPD points and license renewal as important factors influencing CPD participation by nurses. Education level was a significant factor associated with nurse participation in CPD, multiple binary logistic regression model indicated that those with certificate and diploma level of education were less likely to participate in CPD compared to those with degree and above levels (OR; 95% CI: 0.209; 0.062-0.705 and 0.703; 0.254-1.942) for certificate and diploma respectively. Conclusion and Recommendations: Individual factors were the most important factors influencing nurses’ participation in CPD coupled with professional/organizational needs. The study recommends that, CPD for nurses should be jointly planned and implemented by nurses and coordinators of CPD. Individual and professional/organizational motivators of CPD for nurses should be promoted.