I describe habitat use, diet, and male and female reproductive cycles of Takydromus sauteri, an oviparous grass lizard inhabiting Orchid Island, a tropical island off the southeastern coast of Taiwan. All T. sauteri were observed on leaves of Japanese silver-grass (Miscanthus floridulus) at the forest edge. The diet of T. sauteri consisted mostly of spiders (35.7%) and Hemipterans (14.3%). Two prey categories, spiders and gymnoceratans, numerically dominated the diet. Two lizards' stomach contained plant seeds, and two had eaten roaches. Mean snout–vent length (SVL) of adult males (N = 59) was 64.2 (range: 60.3–73.7) mm and that of females (N = 63) was 67.1 (range: 50.6–76.5) mm. Females exhibited spring and summer vitellogenesis with parturition occurring from February to August. Onset of vitellogenesis showed a negative correlation with mass of female fat bodies. Females produced one to four eggs per clutch, and clutch size was not correlated with SVL. Two clutches were recorded during a single year in some individuals. Male fat bodies exhibited the lowest mass from January to July, coincident with the period of reproductive activity.