The main objective of this study was to explore the effects of working conditions on performance of employees of Kenya Commercial Bank. Specifically the study sought to; assess the effect of physical conditions, explore the effect of occupational health and safety and analyse the effect of internal organisational communication on performance of employees of Kenya Commercial Bank. A sample of 172 employees was subjected to stratified random sampling. Primary data was collected by use of questionnaires. Data was Analysed with the aid of Microsoft Excel and SPSS (version 20) and presented in the form of frequency distributions, means and standard deviations. A regression model was developed to establish the relationship between the independent variables and the dependent variable. The regression model showed that Physical Conditions had the greatest effects on the performance of employees of Kenya Commercial Bank followed by Internal Organisational Communication while Occupational Health and Safety had the least effect. Working conditions have a positive effect on performance of employees. The study recommends that Kenya Commercial Bank should put more effort in ensuring that working conditions are favourable and focus more on the physical conditions which has the greatest effect on performance of employees.