The life history and production of Caenis latipennis Banks (Ephemeroptera: Caenidae) is described from Honey Creek, Oklahoma. Emergence behavior, fecundity, voltinism, and secondary production were analyzed. C. latipennis had an extended emergence with five peaks. Females emerged, molted, mated, and oviposited in an estimated 37 min. Mean fecundity was 888.4 ± 291.9 eggs per individual (range, 239–1,576). Adult female head capsule widths in spring were significantly larger than in summer and fall. Compared with the other seasons, fecundity was significantly higher in early summer when densities were lowest. C. latipennis exhibited a multivoltine life cycle with five overlapping generations. Estimated annual secondary production for C. latipennis in Honey Creek was 4,404.28 mg/m2/yr, mean standing stock biomass was 274.64 mg/m2/yr, cohort production:biomass ratio was 5.79, and the annual production/biomass rate was 16.04/yr/yr. Standing stock biomass ranged from 7.6 to 705.4 mg/m2 during the year. Standing stock biomass did not vary significantly among seasons.