Selected effective training methods are considered as learning objectives and key elements of the training plans. This study has been done with the aim of comparison the effectiveness of” Heart dysrhythmia training by two methods of multimedia and lecturing to the nursing students’ knowledge retention”. In a quasi-experimental study, 45 nursing students were randomly allocated to two groups in semester 7 (group lecturing and multimedia) to teach in the first semester 2013, respectively. Moreover, 20 multiple-choice questions were used to test students' knowledge in three stages: before, after and reminding (2 months after the intervention). Then data were analyzed with software SPSS 19 at 95% significance level. Although, no significant differences in mean scores were observed between the two groups before intervention (p>0.05), the students' level of knowledge of both methods increased after the intervention compared to pre- (p>0.001). In addition, in reminding phase the scores in the group trained with multi-media software and lecturing were significantly different between groups (p<0.05). According to results, the effectiveness of lecture and multimedia software at posttest indicated the usefulness of both methods, however, to increase the preservation and conservation of students’ knowledge, using multi-media software offered.