Full text available at http://www.sciedu.ca/journal/index.php/ijhe/article/view/3271/1978Work stress has been identified as a common phenomenon in the teaching profession. However, little research has been done to examine the prevalence of and factors associated with work stress among employees in university context in Tanzania and sub-Saharan African countries in general. Using survey design within the quantitative approach, this study investigated the prevalence of and factors causing work stress among academic staff in public and private universities. The results show that a significant proportion of academic staff reported experiencing high stress, with respondents in public universities reporting being more stressed than their counterparts in private universities. Three factors have been identified as particularly associated with work stress among academic staff. These are lack of staff involvement in institutional reform processes, lack of necessary support systems related to their work and high workload levels. Highly qualified and experienced staff reported lower levels of stress than staff with low qualifications and less experienced. These results indicate that work stress is a common phenomenon among institutions of higher education with its associated consequences such low job satisfaction, which is likely to affect staff’s productivity.