This research investigated the human awareness of hazardous activities and its effects on market fire in Nigeria. Three (3) main markets with high commercial activities selected for this study include Tejuosho market in Lagos, Mile 1 market in Port Harcourt and Ochanja market in Onitsha. Ten hazardous activities were identified within these selected markets. Methods for information gathering include interview, literature review, questionnaire, Occupational Health and Safety Standards (OHSAS) risk estimating procedures and statistical analysis tools.Results showed that human awareness of safety rules has significant effects on the annual level of market fire incident in Nigeria. Analysis of these hazardous activities indicated maximum risk score of 3000 and minimum of 9 for different risk consequences. The relationship of risks to fire incidents were directly proportional indicating that risk at 100, 200, 500, 1000, 2000, and 3000 results in 55, 109, 293, 545, 1090 and 1637 incidents respectively. Test of significance (t-statistics) from risk scores caused by hazardous activities at s=100 (major accidents) and s=40 (few accidents) indicated great significant. The study concluded that market fire incidents will significantly be reduced annually if the frequency of hazardous activities were reduced or totally avoided. The researchers recommended the need for fire Professionals to enlighten traders on proper management of hazardous activities before setting up active and passive tools for fire prevention and control.