Hymenopterous parasitoid species and their parasitism were investigated on ratoon rice plants in paddy fields in the period of early to middle October 1990, immediately before the Maha rainy season in Sri Lanka. The following five species were observed in the galls of the rice gall midge, Oreseolia oryzae (Wood-Mason) on secondary tillers from rice stubbles; Eurytoma sp. (Eurytomidae), Neanastatus cinctiventris Girault (Eupelmidae), Obtusiclava oryzae Subba Rao (Pteromalidae), Platygaster oryzae (Cameron) (Platygastridae), and P. foersteri (Gahan). The species, Eurytoma sp. may possibly be the first record in Sri Lanka, although one specimen of a pupa of Eurytoma sp. was collected at Gampaha District in 1989. P. oryzae and N. Cinctiventris were most abundant among these species. The highest percentage parasitism of P. orizae, i.e. 68.2%, was recorded as a sampling site in Mawatura, Nuwara Eliya District. The highest incidence of N. Cinctiventris took place at sampling sites in Mawanella and Hingula in Kegalla District and percentage parasitism by this parasitoid of the host pupae was 52.1% in this District. From these results, it is concluded that these parasitoids pass through the season, even though rice plants are not cultivated, mainly in the galls on secondary tillers which sprout from rice stubbles.