Background: Striae Gravidarum is a physiological skin change that many females experience during pregnancy and causes stress and concerns about their beauty, self-esteem and other psychological problems, by irritation and even ulcers in the affected areas. Objectives: This study was performed to evaluate the effect of sesame, sweet almond, and sesame and sweet almond oil on prevention of striae (primary outcome) in primiparous females. Methods: This triple-blind randomized controlled clinical trial was done on 200 18 to 35-year-old primiparous females at five governmental health clinics affiliated to Arak University of Medical Sciences, Iran. The subjects were allocated to three intervention groups and one control group by four and eight block randomization and allocation ratio of 1:1:1:1. The strategy used for analyzing data was intention to treat analysis. The intervention groups and control group received 1cc sesame, 1cc sweet almond and sesame oil, 1cc sweet almond oil, and 1cc Placebo, respectively, two times (1 mL twice daily without massaging the abdomen) for 20 weeks. One-way analysis of variance (ANOVA), chi-square, Kruskal-Wallis and binary logistic regression were used to analyze data. Results: Striae at 35 to 38 weeks of pregnancy were observed in 59.2%, 16.7%, 14% and 82% of participants in sweet almond, sesame, sesame & sweet almond oil and control groups, respectively (P < 0.001). The occurrence risk of striae was significantly decreased in the sesame (adjusted OR = 0.04, CI = 0.01 to 0.13), sweet almond (0.27, 0.10 to 0.72), and sesame & sweet almond oil (adjusted OR= 0.03, CI = 0.01 to 0.10) groups, compared with the control group. Abdominal itching was significantly different (P < 0.001) among consumers of sweet almond (65.3%), sesame (10.5%), sesame & sweet almond oil (44%), and control group (78%). Conclusions: The sesame oil, sweet almond oil and their combination was effective in reducing the occurrence of abdominal steriae and its itching.