Abstract This study was performed to determine if the Japanese quail, Coturnix coturnix japonica, could be infected experimentally with the cecal worm, Heterakis gallinarum (=gallinae), or the protozoan, Histomonas meleagridis. Bigland et al. (1965) reported that Japanese quail were refractory to experimental infections with H. gallinarum and H. meleagridis. Conversely, Edgar et al. (1964) noted that this quail was susceptible to both organisms. Cram (1927) listed C. coturnix as host of H. gallinarum and Kurtpinar (1957) found the nematode in 92.2% of the C. coturnix examined in Turkey. Data from the present study confirm Edgar’s et al. (1964) report on the susceptibility of Japanese quail to H. gallinarum, but the data also show this quail may not be susceptible to H. meleagridis or the enterohepatitis caused by it. Straight-run Japanese quail were reared in battery cages on a commercial ration. In experiments 1 and 2, 200 ± 20 larvated H. gallinarum …