The collembolan Proisotoma minuta (Tullberg) was successfully maintained in a laboratory culture that could be used to produce large numbers of P. minuta of standard size and physiological condition. The general life history of P. minuta was studied using a substrate comprising a mixture of plaster of Paris and charcoal with baker's yeast as food. The mean time taken for eggs to hatch following oviposition was 10.6 ± 1.3 days at 17.5°C and 6 ± 0.5 days at 23°C. Conditions in the culture were very important for the production of large insect populations. Growth of the cultures was limited by the increasing population size and was probably affected by contamination of the habitat by the deposition of excretory materials. Proisotoma minuta from a population that had ceased egg production started oviposition after individuals were transferred to a fresh plaster of Paris and charcoal habitat.