Objective: to verify the effectiveness of telenursing in the control of nausea and vomiting induced by antineoplastic chemotherapy. Method: a randomized controlled trial of 61 cancer patients undergoing outpatient chemotherapy treatment, randomized into experimental group and control group. Nausea and vomiting were evaluated by the instrument Multinational Association on Supportive Care in Cancer. The telephone intervention was performed four times after chemotherapy. To verify the effects of this on the variables, the Mann-Whitney test and Student's t-test were used. Wilcoxon signed-rank test was applied to confirm the hypothesis of differences in the pre- and post-test intragroup scores. Results: the groups were homogeneous regarding sociodemographic and clinical characteristics. The experimental group showed a statistically significant reduction in the occurrence of nausea (p=0.0089), in the degree of nausea, in two moments, between 24 hours and three days, and three days and five days (p=0.007 and p=0.009, respectively), in the occurrence of vomiting (p=0.008) and in the number of vomiting episodes (p=0.020). Conclusion: telephone intervention is a potential nursing intervention to reduce nausea and vomiting associated with antineoplastic chemotherapy. Brazilian Clinical Trial Registry: RBR-6s8qm5.