This study investigates the impact of strategies on performance in Taiwan's property and casualty insurance industry. Using the data of property and casualty companies in Taiwan from 1985 to 2004, we initially utilize the hierarchical cluster analysis to examine if there are various strategic groups existing in the insurance market according to their strategic dimensions and verify the clustering accuracy through classification matrix. Further, we carry out a panel data regression analysis to identify the strategies that significantly affect the insurers' performance. The findings reveal that there exist strategic groups and their underwriting performance varies significantly. The results also indicate that size, age, leverage and investment influence the insurers' underwriting performance significantly and positively.