Healthcare professionals such as nurses encounter various health hazards that affect their work performance. This is because they work in extremely stressful conditions which tend to distort their emotional balance resulting into pervasive feelings of frustrations and hopelessness. Previous studies have reported varying outcomes regarding how stress affects job performance of nurses. This study sought to investigate the effect of stress on performance of nurses in public hospitals in Nakuru County, Kenya. The study population comprised of 21 departmental wards-in-charges and 345 nurses from health facilities in Nakuru county. Purposive sampling was used to select all the nurses in the critical care units in selected health facilities in Nakuru County with a total of 187 nurses. Closed ended questionnaires with likert scales of five response categories were used to collect data. Data was collected after approval from the national commission for science, technology and innovation in Kenya. Quantitative data was analyzed using both descriptive and inferential statistics with the aid of the Statistical Package for Social Sciences (SPSS) version 25. The study established stress management significantly predicted the nurses’ performance. Nurses who managed stress were 15.333 times more likely to perform better than nurses who were not able to managed stress.