This research examines the relationships among portfolio concentration, fund manager skills, and fund performance in Taiwan's equity mutual fund industry, yielding several empirical findings as follows. First, after controlling for other factors, concentrated equity funds tend to have smaller net asset values, larger fund flows, higher turnover rates, and a younger age and prevail in smaller fund families. Second, concentrated fund managers buy and sell stocks more smartly based on economic trends or market factors than do diversified fund managers, i.e., they have better market‐timing abilities. Third, only partial evidence supports the premise that concentrated equity funds have better next‐quarter risk‐adjusted performances than do diversified ones, as these fund managers' skills positively correlate to risk‐adjusted fund performance. Fourth, fund managers who have better stock‐picking abilities and intensively invest in certain industries generally exhibit better Carhart's alpha in the next quarter than do other fund managers. Fifth, fund managers' stock‐picking abilities more closely relate to long‐term performance than do their market‐timing abilities. Lastly, positive performance persistence is much stronger than negative performance persistence, but concentrated funds do not have stronger performance persistence than do diversified funds.