There is a large demand for rainbow smelt as a bait and food fish, and culture of the species has economic potential. In 1979, we began experiments to define optimum conditions for incubation of eggs and growth of larvae and juveniles. Hatching success was 40–80% in fresh and brackish water, but zero in full-strength seawater. The timing of hatching was determined for incubation temperatures of 6 to 20°C. Larvae fed most successfully in full-strength seawater on the cultured marine rotifer Brachionus plicatilis. Eyed eggs were also stocked in two ponds, one newly constructed and one with a well-established food base. Larval fish raised exclusively with natural foods (primarily cyclopoid copepods, chironomids, and Chaoborus sp.) reached 44 mm total length within 6 months in the newly constructed freshwater pond, and 83 mm in the established pond; rates of 0.22 and 0.41 mm/day, respectively. Rainbow smelt in the latter pond reached commercial baitfish size before the first winter of life. Fish in the established pond averaged 119 mm in less than 13 months, including a long period of minimal winter growth.