Ozark bass (Ambloplites constellatus) are endemic to the White River drainage in northern Arkansas and southern Missouri. Although they are assumed to be similar to rock bass (A. rupestris), little is known of their behavior or life history. We investigated the spawning behavior and ecology of Ozark bass by snorkeling and seining in the Buffalo National River, Arkansas, from 1990–1992. Most males nested on gravel or cobble substrates. In 1992 65% of nests occurred within 1 m downstream of cover. Egg deposition was asynchronous, but began when water temperatures reached 17 C. Embryos hatched in 5 d at a mean water temperature of 21 C and free-embryos remained in their nests for up to 9 d before swim-up. Predation and high water limit Ozark bass spawning success in the Buffalo River. No nests in our study area successfully produced dispersing young in 1991, while 10% of nests monitored in 1992 were successful. Young-of-year were difficult for divers to locate during the day in 1990–1992 and were caught in seine hauls at night, but not during the day, suggesting that they may be nocturnal at this stage.