Trichogrammatid egg parasitoids (Hymenoptera: Trichogrammatidae) of rice leafhoppers and planthoppers (Hemiptera: Cicadellidae and Delphacidae) known from Taiwan are identified taxonomically and illustrated, and their host associations are determined by rearings using sentinel eggs of the key pest species. The previously published records of such egg parasitoids in Taiwan are critically analyzed in the unfortunate absence of almost any voucher specimens. Pseudoligosita nephotetticum (Mani) is shown to be the most common egg parasitoid of the two leafhopper and three planthopper pests of rice in Taiwan: the zig-zag leafhopper Maiestas dorsalis (Motschulsky) (a new host record), the green rice leafhopper Nephotettix cincticeps (Uhler), and the delphacids Laodelphax striatella (Fallén) (small brown planthopper), Nilaparvata lugens (Stål) (brown planthopper), and Sogatella furcifera (Horváth) (whitebacked planthopper). Paracentrobia (Brachistella) andoi (Ishii) syn. nov., originally described from Japan as Japania andoi Ishii, and Paracentrobia (Brachistella) garuda Subba Rao syn. nov. from Thailand are synonymized under Paracentrobia (Brachistella) bicolor (Girault) from northern Queensland, Australia; Pseudoligosita tachikawai (Yashiro) syn. nov., originally described as Oligosita tachikawai Yashiro from Japan, is synonymized under Pseudoligosita nephotetticum. Lectotypes are designated for Japania andoi and Oligosita shibuyae Ishii.