SUMMARY Clinicopathological analysis and growth rate study of 100 cases of ameloblastoma was undertaken. The tumour had site predilection for the mandible (91.0%) and occurred more in males than in females (ratio 1:0.9). 62.0% of patients in the series were less than 20 years of age. The estimated monthly growth rate (EMGR) of ameloblastoma was observed to be slower in males although the mean tumour volume recorded in females was lower than males in the series. The biologic aggression of 4 various types of ameloblastoma was predicted using EMGR and average volume of tumour at hospital presentation as predictive markers. Solid multicystic ameloblastoma was observed with the fastest EMGR of 0.81 cm(3)/month. Peripheral ameloblastoma was observed with the slowest EMGR of 0.17 cm(3)/ month. It was concluded that all the 4 types of ameloblastoma observed were clinically distinct and showed varying biologic aggression. The solid multicystic type with the highest growth rate (0.81 cm(3)/month) was considered the most aggressive while the peripheral type (growth rate = 0.17 cm(3)/month) was the least aggressive. It is therefore necessary to distinguish between the various clinical types of ameloblastoma before a clinician proceeds with definitive treatment.