The results in Table 13 revealed that the work performance mean score (M = 3.73, SD = 0.40) of police officers exposed to moderate occupational stress level was higher than that (M = 3.52, SD =0.36) of their colleagues exposed to high occupational stress level. The results also revealed that the difference between the mean of the two groups were statistically significant at the 0.05 level, t(82) = 2.484, p < 0.05. The significant difference in work performance was attributed to the effects of occupational stress. The implication of the results is that there is a negative relationship between the two constructs as the work performance of a police officer deteriorates as he/she is exposed to higher levels of occupational stress. The study observed that, occupational stress has a negative effect on the work performance of police officers. These findings are in line with those of Greenberg and Baron (2000) who noted that occupational stress reduces efficiency, decreases capacity to perform, dampens initiative and reduces interest in working, increased rigidity of thought, and lack of concern for the organistion, colleagues and a loss of responsibility. The results also consisted with the findings of Shane (2008) who noted that police officers were of the view that work related stress impacts negatively on their work performance.