Background: Today, leukemia is one of the most important health challenges in the world. Despite the many advances in malignancy treatment, children undergoing chemotherapy are still suffering from deliberating side effects. So, pediatric oncology nurses play a main role in the management of those children. Objective: this study aimed to identify the effect of peppermint inhalation on chemotherapy induced nausea and vomiting in children with leukemia. Design: A quasi-experimental research design. Setting: The study was conducted at the Inpatient and Outpatient Hematology/leukemia Unit at Smouha University Children's Hospital at Alexandria. Subjects: A convenience sampling of 50 children with leukemia comprised the study subjects, their ages ranged from 6-15 years and a healthy sense of smell, no history of asthma or chronic obstructive pulmonary disease; no allergy to plants or essential oils. The study subjects were randomly assigned equally into two groups (control and peppermint inhalation groups). Tools: Three tools were used: Tool I: Socio Demographic and Medical Data of Children with Leukemia Undergoing Chemotherapy Assessment Sheet, Tool II: Assessment of Nausea and Vomiting of Children with Leukemia Interview Schedule, and Tool III: Assessment of Severity of Nausea and Vomiting by Baxter Retching Faces (BARF) Scale. Results: The study revealed that children who received peppermint inhalation had a significantly lower mean total score of chemotherapy induced -nausea and vomiting through the three studied sessions compared to those in control groups (P =0.000). Conclusion: It can be concluded that the peppermint inhalation therapy may have significant antiemetic effects as alleviating the CINV for children with leukemia. Recommendations: Pediatric oncology nurses should incorporate peppermint inhalation therapy in pediatric oncology unit protocols for management of chemotherapy induced -nausea and vomiting.