Background Equity in healthcare services utilization is on the agenda for both research and policy makers, especially after the Millennium Development Goals. Despite the recognition of the importance of mental health services utilization, equity in terms of access has not been widely researched. Objective This study aims to investigate the degree and progress of equity in mental healthcare services utilization in Turkey from a gender perspective. Methods The Horizontal Inequity (HI) index is calculated using a nationally representative dataset from the Health Surveys (2014 and 2016) conducted by the Turkish Statistical Institute. The index is calculated for males, females, and all individuals separately to identify gender differences. Results The results from the HI index indicate pro-poor inequities in the utilization of mental healthcare services in Turkey for both 2014 and 2016. For all individuals, the standardized HI indices were found to be - 0.3320 and - 0.3374 for 2014 and 2016, respectively. In 2014, the standardized HI indices were calculated to be - 0.3504 and - 0.3173 for males and females, respectively. In 2016, the HI indices were found to be - 0.3241 and - 0.3541 for females and males, respectively. Conclusions There is a great need for gender-focused policies to improve horizontal equity in mental healthcare services utilization.