This study used Hypnofertility-based interventions to determine whether these interventions would lead to increased fertility preparedness and pregnancy outcomes and decreased cortisol levels in women undergoing In Vitro Fertilization (IVF) treatment. This randomized, controlled, prospective study was conducted from November 2017 through March 2019 in 61 Turkish women with unexplained infertility (intervention group: 30, control group: 31). Hypnofertility-based nursing care included affirmations, visualization, imagination, and relaxation from the first day of treatment until the day of the pregnancy test. The Fertility Preparedness Scale, a saliva sample for cortisol level, and the pregnancy test results were used for data collection. Hypnofertility-based nursing care decreased the cortisol levels of women in the intervention group compared to that in the control group (p = 0.00). Though fertility preparedness was higher in the intervention group, the difference was not statistically significant (p = 0.13). Although interventions relieved the women during the treatment process, there was no anticipated effect on pregnancy outcomes (p = 0.75). Hypnofertility-based nursing care significantly reduce the cortisol levels, suggesting that the intervention helped women relax. [ABSTRACT FROM AUTHOR]