Background & aim: Nausea and vomiting during pregnancy (NVP) is among the most common problems in pregnant women. As explained in guidelines, combination of non-drug treatments, including nutritional modifications, lifestyle changes, and use of alternative medicine for the treatment of NVP has been less highlighted. The present study was performed with the aim of determining the effect of an educational intervention (based on the Ottawa nutritional guideline) on health-related quality of life in pregnant women with NVP. Methods: This single-blind clinical trial was performed on 60 pregnant women, referred to Daneshamouz and Ahmadi health centers in Mashhad, Iran in 2015. The intervention group received two 60-min training sessions based on the Ottawa nutritional guideline, while the control group received routine care. The data collection tools included the subject selection form, demographic and midwifery information form, health-related quality of life for nausea and vomiting during pregnancy (NVPQOL) questionnaire, and the Ottawa guideline checklist. For data analysis, Chi-square, Fisher’s exact test, Mann-Whitney test, independent t-test, paired t-test, and ANOVA were performed, using SPSS version 16. P-value less than 0.05 was considered statistically significant. Results: The demographic characteristics of the subjects such as education, occupational status, age, gestational age, and body mass index were homogenous in the two groups. The mean NVPQOL score was significantly different between the intervention and control groups after the study (p <0.001). Also, the difference between the pre- and post-intervention scores was significant in the intervention group (p <0.001). Conclusion: Based on the findings, training based on the Ottawa nutritional guideline could improve health-related quality of life in women with NVP; therefore, this type of training is recommended as an effective method.