Noncompliance with prescribed therapy significantly impacts dialysis patient care and outcome. At least one-half of hemodialysis (HD) patients are likely to be noncompliant with some part of their treatment regimen, and one-third of peritoneal dialysis (PD) patients are believed to miss prescribed exchanges. Psychosocial issues, younger age, and smoking behavior have been linked with compliance problems in multiple studies. Few interventions have been rigorously tested, but patient education and/or individualized attention, supervision, encouragement, and support are widely advocated strategies to improve patient compliance. Areas in need of continued study include psychosocial determinants of compliance in PD as well as HD patients, compliance behavior patterns over time, and the parameters within which dialysis compliance can vary and still achieve specified treatment goals.