Introduction: Although continuing education is necessary for practicing nurses, it is very difficult to organize traditional classes because of large numbers of nurses and working shifts. Considering the increasing development of mobile electronic learning, we carried out a study to compare effects of the traditional face to face method with mobile learning delivered as text messages by cell phone. Materials and Methods: Sixty female nurses working in our hospital were randomly divided into class and short message service (SMS) groups. Lessons concerning breast cancer screening were prepared as 54 messages and sent in 17 days for the SMS group, while the class group participated in a class held by a university lecturer of breast and cancer surgery. Pre- and post-tests were undertaken for both groups at the same time; a retention test also was performed one month later. For statistical analysis, the paired T test and the independent sample T test were used with SPSS software version 16; p<0.05 was considered significant. Results: Mean age and mean work experience of participants in class and SMS groups was $35.8{pm}7.2$, $9.8{pm}6.7$, $35.4{pm}7.3$, and $11.5{pm}8.5$, respectively. There was a significant increase in mean score post-tests (compared with pretests) in both groups (p<0.05). Although a better improvement in scores of retention tests was demonstrated in the SMS group, the mean subtraction value of the post- and pretests as well as retention- and pretests showed no significant difference between the 2 groups (p=0.3 and p =0.2, respectively). Conclusions: Our study shows that teaching via SMS may probably replace traditional face to face teaching for continuing education in working nurses. Larger studies are suggested to confirm this.