This paper assessed the effect of the health condition of employees on the performance of small and medium-scale firms in Nigeria. The cross-sectional survey design was utilized and a questionnaire was administered to three hundred and fifty-three (353) employees of small and medium-scale firms in three (3) states of the south-east geopolitical zone of Nigeria namely Anambra, Enugu and Imo. The data obtained from the field survey were analyzed via descriptive and inferential statistical tools. The findings of the study showed that the health condition of employees significantly contributes to the performance of small and medium-scale firms in Nigeria. Based on the findings of the study, it was recommended among other management of small and medium scale firms should consider investing in the wellbeing of employees in order to ascertain their health condition. As a matter of fact, small and medium scale firms can actualize this via the provision of health insurance schemes, mental health promotion and support for mental illness, health promotion via physical activity and nutrition programmes among others. As a matter of urgency, the management of small and medium scale firms should formulate programmes aimed at improving occupational health safety