ABSTRACT This paper reviews reproduction and mating in ostracodes. Both sexual reproduction by copulation and parthenogenesis occur in ostracodes. The group is large and there is much variation in their reproductive patterns, especially between the two major groups: the podocopans and the myodocopans. The following features of ostracodes are reviewed: (1) life history patterns (egg production and protection, developmental patterns, longevity, seasonality of breeding, sex ratios), (2) reproductive system morphology (including gonads, sperm, seminal vesicles, spcrmatophores and copulatory apparatuses in males, and gonads and seminal receptacles in females), (3) secondary sexual characters (especially in the valves, limbs, and eyes), (4) mating positions and copulation, (5) courtship and precopulatory sexual behavior, and (6) bioluminescent displays.