This study was conducted to determine the effect of biological nurturing on breastfeeding success and self-efficacy in primiparous women. This randomized controlled study was conducted with 130 mothers who had a caesarean section (65 experimental, 65 control). However, it was determined that experiment group had statistically higher LATCH score average than control group in all of the measurements at 8th, 24th and 48th hours after labour (p < 0.001). According to LATCH average scores, it was determined that eta-squared value was 0.77 (high impact level) for experiment group and 0.15 (high impact level) for control group. It was determined that BSES post-test total average score was 60.74 ± 6.75 in experiment group and 45.23 ± 10.59 in control group and this difference was statistically significant (t = 9.955; p = 0.000). It was determined that biological nurturing significantly increased breastfeeding success and self-efficacy in primiparous women.