Forty-eight chronic hemodialysis (HD) patients (pts) completed questionnaires that used linear analogue scales (LAS), yes/no responses, and demographic data collection to characterize sleep disorders. Twenty-five pts (52%) reported problems sleeping. These pts graded sleep problems significantly higher than those without sleep problems (6.5 +/- 3 vs. 1.8 +/- 2, p less than 0.001 by LAS). Those with sleep disorders were more likely to smoke cigarettes (13/25 vs. 6/23, p less than 0.05) and have bone pain (14/25 vs. 6/23, p less than 0.05). No differences among pts with and without sleep problems were seen in age, gender, time on dialysis, caffeine intake, pruritus, feelings of sadness, worry, or anxiety, or Kt/V values (1.5 +/- 0.2 vs. 1.4 +/- 0.2, p less than 0.13). Restless legs (84%), onset insomnia (76%), and nighttime (76%) and early A.M. waking (72%) characterized the sleep disorders; symptoms suggesting nocturnal myoclonus were less common (20%). We conclude that sleep disorders are common in HD pts and may be exacerbated by tobacco use, bone pain, and restless legs. Kt/V does not correlate with sleep disorders. Further examination of this problem, including formal sleep studies, is needed.