BACKGROUNDThe objective of this study was to test the efficacy of an individualized uncertainty management intervention delivered by telephone to Caucasian and African‐American men with localized prostate carcinoma and directed at managing the uncertainties of their disease and treatment.METHODSThe authors delivered a psychoeducational intervention by phone to men with prostate carcinoma, with or without supplemented delivery to a close family member, that was directed at managing uncertainty and improving symptom control. One hundred thirty‐four Caucasian men and 105 African‐American men were assigned randomly to one of two approaches to delivering the intervention or to the control condition. Men entered the study immediately after surgical treatment or in the first 3 weeks of radiation therapy. Trained nurses delivered the intervention through weekly phone calls for 8 weeks.RESULTSThe authors found that the majority of intervention effects were from baseline to 4 months postbaseline, when treatment side effects are most intense. Both Caucasian men and African‐American men who received either one of the two approaches for delivering the intervention improved in the two uncertainty management methods of cognitive reframing and problem solving. Similarly, when the intervention groups were combined, men who received the intervention also improved significantly in control of incontinence by 4 months postbaseline. Decreases in the number of treatment side effects differed by time and treatment/ ethnic group interactions as did satisfaction with sexual functioning.CONCLUSIONSThis is one of the first tests of a psychoeducational intervention among men with prostate carcinoma and was the first test that included a sufficient number of African‐American men to test by ethnic group. Therefore, replication of these findings is advised. Cancer 2002;94:1854–66. © 2002 American Cancer Society.DOI 10.1002/cncr.10390