Two nematode species, one acanthocephalan species, and unidentified cestodes were recovered from a total of 481 northern bobwhites (Colinus virginianus) collected from January 1982 to December 1983 in southern Texas. The nematodes Aulonocephalus lindquisti and Trich-ostrongylus tenuis varied in prevalence with month and locality. Mediorhynchus papillosis was recovered from only two birds. Monthly and yearly rainfall patterns were not correlated with endoparasite intensity and prevalence, which indicates that fluctuations of populations of northern bobwhites in Texas may be caused by factors other than changes in prevalence and intensity of endoparasites.