The relation between reservoir hydrology and recruitment of black crappies Pomoxis nigromaculatus and white crappies P. annularis was examined in 11 reservoirs throughout Alabama from 1990 to 1996. Estimates of recruitment were derived from catch rates of age-1 fish in the fall with trap nets and from residuals associated with catch-curve regressions of age 3–7 fish captured in the spring with electrofishing gear. Reservoirs were separated into three hydrologic categories: (1) eight reservoirs with short retention (volume/discharge) times (2–9 d) that fluctuated less than 1 m/year; (2) two reservoirs with longer retention times (44–55 d) that generally fluctuated 1.8 and 4.6 m/year; and (3) one reservoir that fluctuated 1.8 m/year with a relatively short retention time of 15 d. In the reservoirs with low retention times and stable water levels, greater year-class production was related to low winter (January–March) retention before crappie spawning and to higher postwinter (April–December) retention when these fish were age 0. These variables explained about 60% of the variation in crappie year-class abundance. Higher production of young crappies was nearly always associated with both winter retention of 6 d or less and postwinter retention greater than 11 d. In these reservoirs, cyclic crappie recruitment appeared to be influenced by climatic conditions. In the three reservoirs that fluctuated 1.8 m or more per year, short winter retention and higher water levels in winter before crappie spawning were both associated with greater year-class abundance; hydrologic conditions during and after crappie spawning were not related to crappie recruitment. In these reservoirs, maintenance of higher water levels in the winter before crappie spawning may enhance reproductive success.