This study aimed to undertake an investigation on the factors influencing management training effectiveness in Commercial Banks of Kenya: A case of Co-operative Bank of Kenya, Nairobi County. The study was guided by three specific objectives: To determine the influence of training design on management training effectiveness in Co-operative Bank, Nairobi County; determine the influence of trainee characteristic on management training effectiveness in Co-operative Bank, Nairobi County and to determine the influence of Training environment on management training effectiveness in Co-operative Bank, Nairobi County. The target population for the study was therefore 282 respondents. Stratified sampling was used to sample the different categories of management staff at Co-operative Bank of Kenya. A questionnaire was used to collect data for this study. The data was analyzed using Statistical Package for the Social Sciences (SPSS). The data was presented in charts, tables and supported with an interpretation and discussion. The findings showed that there were positive and statistically significant associations between training design, trainee characteristics, training environment, and management training effectiveness at Cooperative Bank. The multiple regression analysis showed that the independent variables explained 56.2 % of change in management training effectiveness at 95 % confidence level. Trainee characteristics were found to have the greatest effect on management training effectiveness followed by training design and training environment. The study concluded that trainee characteristics have the greatest effect on management training effectiveness followed by training design, and training environment. The study recommended that Cooperative Bank human resource managers should conduct needs assessments for training programmes; that there should be continuous monitoring of staff fresh from training and provide incentives to motivate staff to enroll in training programmes offered by the organisation; and that supervisors should be encouraged to create environments where staff can apply skills acquired from training in their day-today roles.