Urinary diversion operations (urostomy) patients require a great deal of emotional and physical adjustment. They usually face many problems such as loss of body function and relationship with others, and change in lifestyle. They need to adapt to the external appliance, stoma alteration in toileting habits, skin irritation problems, infection, and odor problems. Self-care for these patients is considered the most important factor that can minimize the complaints and complications. The aim of this study was to evaluate the impact of nursing intervention among urostomy patients regarding practicing self-care. The sample comprised 100 urostomy patients, divided into two groups: 50 study, and 50 control. For both groups, patients' knowledge about urostomy and related self-care performance were assessed before intervention, immediately after, and after six-months follow-up at outpatient clinic. Data were analyzed using Epi-info 6.04 computer software package. Findings revealed statistically significant improvements in knowledge and performance among patients in the study group, compared to the control group. The study group became more knowledgeable about the definition, function, anatomy, and physiology of urostomy, and in self-care performance. The rates of complaints and complications were found to be lower in the study group than in the control one. The study suggests that urostomy patients should receive their self-care training regarding urostomy during hospitalization. Follow-up at outpatient clinic is highly recommended as well.