Six new species of coccidia are described from endangered Phelsuma spp. geckoes (Sauria: Gekkonidae) endemic to Mauritius, Indian Ocean. Five new species (3 Eimeria and 2 Isospora species) are described from Phelsuma rosagularis Vinson et Vinson; all lack a micropyle and an oocyst residuum, and all have a sporocyst residuum. Oocysts of Eimeria swinnertonae sp. n. are ellipsoidal, 22.2 × 17.8 (20.8-24.8 × 16.8-18.4) μm; SI 1.25; polar granule absent. Sporocysts are ellipsoidal, 8.8 × 7.0 (8.0-9.6 × 6.4-8.0) μm; SI 1.3; Stieda body absent. Oocysts of Eimeria stebbinsi sp. n. are ellipsoidal, 17.4 × 11.7 (16.0-19.2 × 11.2-12.8) μm; SI 1.5; polar granules present. Sporocysts are elongate-ellipsoidal, 7.7 × 4.0 (7.2-8.0 × 3.2-5.6) μm; SI 1.9; Stieda body present. Oocysts of Eimeria raleighi sp. n. are spheroidal to sub-spheroidal, 17.0 × 15.5 (16.0-19.2 × 14.4-16.8) μm; SI 1.1; polar granule present. Sporocysts are sub-spheroidal, 7.8 × 6.6 (7.2-8.0 × 6.4-7.2) μm; SI 1.2; Stieda body absent. Oocysts of Isospora cottinghamae sp. n. are ellipsoidal, 19.8 × 15.5 (17.6-21.6 × 14.4-17.6) μm; SI 1.3; polar granules present. Sporocysts are ellipsoidal, 10.8 × 6.9 (9.6-12.8 × 6.4-8.0) μm; SI 1.6; Stieda body present. Oocysts of Isospora pearlae sp. n. are ellipsoidal, 16.0 × 11.5 (15.2-17.6 × 9.6-12.8) μm; SI 1.4; polar granule present. Sporocysts are ellipsoidal, 8.8 × 5.4 (8.0-9.6 × 4.8-6.4) μm; SI 1.6; Stieda and substieda bodies present. One new Eimeria species is described from the blue-tailed day gecko, Phelsuma cepediana Merrem. Oocysts of Eimeria hartleyi sp. n. are sub-spheroidal to ellipsoidal, 18.2 × 14.5 (16.0-20.8 × 13.6-16.0) μm; SI 1.26; polar granules present. Sporocysts are ellipsoidal to cylindroidal, 7.5 × 5.3 (6.4-8.0 × 4.8-6.4) μm; SI 1.4; Stieda body present. We report the presence of tetrazoic spheroidal to sub-spheroidal oocysts or sporocysts 10.2 × 8.5 (9.9-10.4 × 8.3-8.8) μm; SI 1.2 from an individual of P. cepediana. These oocysts or sporocysts are significantly larger than the Cryptosporidium species so far described from reptiles, and likely represent excretion of spuriously ingested sporocysts of a Sarcocystis or Adelina coccidian.