Business performance has attracted researchers' attention in the previous literature of corporate finance. However, in the framework of the life insurance sector, they have given a number of attentions. In our paper, we investigate empirically the effect of firm-specific characteristics (size, leverage, tangibility, risk, growth, liquidity and age) on the profitability of eight Tunisian insurance companies during the period of study from 2005 to 2015. The empirical results show that the variables size, age and growth are the most important determinants of the performance of Tunisian insurance companies as measured by Return on Asset ratio. Then, leverage, tangibility, liquidity and risk don't affect the performance of Tunisian insurance companies.