Introduction: The incidence of chemotherapy-induced late emesis and vomiting in pediatric oncology patients and the related factors were investigated. Materials and Method: The study consisted of the patients aged between 0-18 years and given chemotherapy between January and December 2009. The amount of vomiting was described on numbers and the grade of nausea was described between 0-10. Vomiting and nausea was evaluated daily by the same clinician. Results: Sixty nine late nausea and vomiting episodes in 35 patients were evaluated. There were 22 females and 13 males in the study group. Mean age was 8.88±5.43 (1 to 17) years. Late nausea was found 2.8% on the first day, 81.1% on the second day, 68% on the third day, 46.3% on the fourth day and 24.6% on the fifth day. Late emesis was found 1.4% on the first day, 65.2% on the second day, 43.5% on the third day, 24.6% on the fourth day and 13% on the fifth day. There was no significant difference in nausea and emesis between boys and girls. There was a positive correlation between the age and nausea/emesis episodes. The correlation coefficients between age and nausea grade on 2, 3, 4 and 5th days were 0.29, 0.27, 0.33, and 0.24, respectively; and p values were 0.013, 0.023, 0.005 and 0.046, respectively. The degree of the emetogenic potential of drugs on the number of emesis and the severity of nausea was found to be not significant. The vomiting was statistically significant on second and third days and grade of nausea on first, second and third days in the patients given cisplatin.Conclusion: In this study, it was found that emesis was most seen in the second day of chemotherapy, the grade of vomiting was higher in patients receiving cisplatin and there is a positive correlation between age and grade of nausea. (Journal of Current Pediatrics 2011; 9: 1-6)