Aim: The aim of this research is to examine the effect of laughter yoga on breastfeeding self- efficacy. Method: The study is randomized controlled experimental type study. The study was carried out at the Family Health Center (FHC) in the city center of a province in eastern Turkey. In the first level; pre-test data were collected from the women who had a 0-1 month old baby and applied to the FHC for various reasons. The women in the experimental group were given laughter yoga. In second step; Data were collected in line with the group (experimental or control) they were assigned by communicating with the women. “Descriptive Information Form” and “Postnatal Breastfeeding Self-Efficacy Scale-Short Form” were used while collecting the research data. Results: In the study, no statistically significant difference was found between the experimental and control group women in terms of socio-demographic characteristics and pre-test breastfeeding self-efficacy score averages (p>0.05). As a result of the six-week laughter yoga practice, it was determined that the breastfeeding self-efficacy score of the experimental group was X̄=48.867 ± 4.51, the mean breastfeeding self-efficacy post-test score of the control group was X̄=41.818 ± 10.73, and the increase in the experimental group was statistically significant (p<0.05). However, in the experimental group; While the increase in breastfeeding self-efficacy post-test value compared to breastfeeding self-efficacy pre-test value was significantly different (p<0.05), in the control group; the increase in breastfeeding self-efficacy post-test value was not significant (p>0.05). Conclusion: As a result, it has been determined that laughter yoga improves mothers’ breastfeeding self-efficacy.