Background: Cesarean section is an important surgical procedure to save mothers and/or babies’ lives. Current trends show that the rate of Cesarean section is increasing dramatically over the years. The aims of this study were to compare the effects of "motivational interviewing" and "information, motivation and behavioral skills” model on choosing mode of delivery among pregnant women.Methods: In a four-armed, parallel-design randomized controlled trial, 120 women were randomly assigned to three brief interventions and one control groups. We recruited pregnant women referring to Ebnesina hospital, Tehran- Iran from 2019-2020. The intervention groups included: 1) motivational interviewing; 2) face-to-face information, motivation and behavioural skills model; and 3) information, motivation and behavioural skills model provided using a mobile application. The inclusion criteria were being literate, gestational age 24 to 32 weeks, being able to speak Persian, having no complications in the current pregnancy, having no indications for CS, and having enough time to participate in the study. The most important outcomes of the study included women’s intentions to undergo any mode of delivery, women’s self-efficacy in choosing the mode of delivery, and mode of delivery. Data were analyzed using descriptive statistics (mean, frequency and standard deviation), inferential statistics including independent t-test, paired t-test, Chi-squared and One-way ANOVA tests and logistic regression.Results: Following the interventions, significant differences were found in the mode of delivery (P < 0.05) and women’s self-efficacy and intention (P < 0.05). Women who had used the mobile application had more improvements in the self-efficacy and intention than the face-to-face intervention groups.Conclusions: Our study showed positive significant effects of various types of brief interventions to reduce unnecessary Cesarean section rate among the participant women. Providing the intervention using mobile application showed even better results. Our findings may contribute to a rise in normal vaginal delivery; and these simple, non-expensive, tailored to women, and culture-oriented brief interventions can be considered as appropriate strategies to reduce Cesarean section rate in local, national, and/or regional levels.Trial registration: This study has been registered in Iran Randomized Clinical Trial Center (IRCT20151208025431N7). Registered October 07, 2018.