Background: Prescription writing is one of the most important stages of medical treatment, and following its principles improves efficiency and effectiveness of treatment. Midwifery students are the group of a medical team who are authorized to prescribe medications. However, clinical evidence suggests that their skills are inadequate in the area. Objectives: Therefore, this study was designed to investigate the effect of a workshop on the prescription writing skills of midwifery students. Methods: This was a quasi-experimental study conducted among 32 senior undergraduate midwifery students. The students were divided into two groups. A two-day workshop was held for each group. Each group was divided into three subgroups for practical work. The training was provided based on the general principles of prescribing in four parts including superscription, general principles of prescription, standard principles of prescription, and instruction of using medications. Adherence to the principles of prescribing by students was evaluated through a checklist before and after training and four weeks later. Data were analyzed with a general linear model and repeated measures analysis. Results: Patient's name was the most common record in the prescriptions. The mean number of drug items was 3.7 ± 0.04, which decreased to 2 ± 0.03 after the intervention. The name and signature of the prescribed drugs were in less than 15% of the prescriptions, with 85% improvement after the intervention. Moreover, 40.6% of the prescriptions were readable, but in none of them, the reason for visit and diagnosis were mentioned (over 50% increases after training). Form of drug, dose and medication number were listed in 45% of the prescriptions that rose to more than 70% in all the three cases. The most responses on the instruction of using the medication were related to the method of use and drug use intervals. Repeated measures ANOVA showed a significant difference in the mean scores of students' prescriptions after education and four weeks after the workshops in all the four parts of prescription principles (P < 0.001). This significant difference was also observed in all four common diseases in gynecology (P < 0.001). Conclusions: The prescription workshop had a significant positive effect on the knowledge and skills of midwifery students in the field of prescription writing. Therefore, this strategy can be used as a useful approach for the rational use of medicines by midwives. Because of the importance of prescription writing, we suggest including it in the curriculum of midwifery students.