Background: Peritoneal dialysis (PD) is an important option for treatment of patients with end stage kidney disease (ESKD). PD is primarily a nursing procedure and needs professionally skilled nurses for optimal performance. The aim of this study was to evaluate the knowledge and competences of nurses working in PD units who had little or no formal prior training courses. Methods: Forty nurses working in four PD centers in Khartoum, Sudan, for one or more years were enrolled in this study. Nine nurses (22.5%) had structured training courses prior to employment, while 31 of them (77.5%) had no formal training in PD care prior to their employment in the centers, and were trained by apprenticeship to senior nurses. A structured face to face interview questionnaire was used to assess nurses' knowledge, and an observational checklist to observe their practical skills. Instrument validity and reliability were tested by a pilot study on five nurses. Pearson correlation coefficient obtained was (r = 81) for the knowledge and (r =74) for the practice. The nurses in the study were divided into four groups, and exposed to educational sessions for knowledge and practical skills at a rate of once per week for six weeks. A post-course assessment of knowledge and skills using the same tools was conducted four weeks after completion of the course. Data was analyzed using paired-sample t-test and 95% C.I. Significance was set at P<0.05. Results: Nurses' knowledge pertaining to ESKD and management of PD and their practical skills improved significantly in most variables tested after the educational and training intervention. The improvement was much more evident in nurses who had no previous structured training in PD management. Conclusion: This study shows that PD nurses who had experience in performing PD procedures for more than one year but had no formal training were deficient in many aspects of proper PD nursing care. On the job-training seems to be not enough to give good knowledge and practical skills in nursing management of PD patients.