One way to improve the sustainability of agricultural systems is to generate similar characteristics to those in natural ecosystems by maintaining energy flows and habitat diversity, thereby ensuring the presence of natural enemies and other beneficial organisms that can regulate pest populations and maintain crop productivity with fewer environmental impacts. The objectives of this study were to identify and compare the diversity of parasitoid assemblages in irrigated rice crops under organic management in a nearby protected area; to compare the efficiency of two kinds of parasitoid traps; and to compare temporal variation in parasitoid species at the two sites. The study was developed in the Banhado dos Pachecos Wildlife Refuge (BPWR) and in Viamão, RS organic rice fields (OR). Specimens were collected monthly from May 2011 to April 2012. Two Malaise and four Moericke traps were used in each area. In the BPWR area, Platygastridae, Ichneumonidae and Braconidae showed the highest abundance (30 %, 21 % and 11 %, respectively), and in the OR area, the dominant taxa were Platygastridae (26 %), Braconidae (18 %) and Encyrtidae (15 %). Malaise traps captured the largest number of parasitoids (58 %). The richness estimators Chao 1, Jack 1 and Bootstrap, pointed to a richness of 229 to 122 species in the OR area and of 454 to 260 in the BPWR area. Parasitoid diversity was higher in the BPWR than in the OR. Parasitoid abundance was highest in the rice crop during months in which crops were growing at the site.