BackgroundIn nursing education, it is important to acquire and assess psychomotor skills. Traditional assessment and evaluation methods are outcome-oriented and educator-centred. In education, there is a greater need for the use of process-oriented and student-oriented complementary assessment methods. AimThe aim of this study is to examine the effect of self and peer assessment training given to nursing students on stoma care skill success. MethodsThis study was conducted using a randomised controlled experimental design model. The sample consisted of a total of 53 students (27 in the intervention group and 26 in the control group). The data were collected using the Information Form, the Stoma Care Skill Rubric, the View Scale for Peer and Self Assessment and the Impression Scale for the Peer and Self Assessment. The intervention group received a training on self and peer assessment. The students were trained on stoma care and they were asked to practice stoma care. The applications were recorded on video. At the end of application, each student in both the intervention and control groups was assessed by himself, his peers and the educator. Number, percentage, mean, standard deviation, Shapiro-Wilk, chi-square, Mann-Whitney U tests were used to analyse the data. ResultsNo difference was found in the stoma care skill scores in the intervention and control groups at the end of stoma care practice. When the stoma care skill scores were examined within the group, there was a significant difference between the self assessment scores and the peer, educator and self-assessment-video watching scores in both groups. No difference was observed between the self assessment-video watching scores and the peer and educator scores. In the intervention and control groups, the scores of the view scale for the peer and self assessment and the scores of the impression scale for the peer and self assessment increased, but there was no significant difference between them. The students stated that they intended to use the self and peer assessment method in other skills as well since it enabled them to notice its mistakes and helped them learn the skill better. ConclusionsIt is recommended that the use of self and peer assessment methods be expanded in nursing education during skill acquisition and assessment practices. It is thought that using video recording, scales, or rubrics in conjunction with these methods would be beneficial.