The effects of soak time and fish density on number and size of white crappie (Pomoxis annularis) caught with trap nets were investigated in Mississippi lakes. Catch/set (1-7 days) of large white crappie (≥200-mm total length) increased asymptotically with soak time, but that of small and medium fish (<130 and 130-199 mm, respectively) decreased after the first 2-3 days. Catch/day of all length groups of white crappie, increased sharply with soak time, peaked in 1-3 days, and decreased thereafter. These trends indicated that catch could be optimized if nets were run every 2-3 days, and that longer soak times could result in the underestimation of small and medium-size fish. Trap net samples taken within 0.4- to 2.4-ha lake enclosures prior to treatment with rotenone indicated that catch/effort in nets reflected absolute abundance of medium and large white crappie within these areas.