Objective This study aimed to assess the adherence to guidelines in the prescription of sodium valproate (SV) to women of childbearing potential (WOCP) in Southern District Mental Health Services (SMHS) in New Zealand (NZ). Methods Electronic records of women aged 18–54 who were newly prescribed SV by SMHS between the 1st of January 2018 and the 31st of December 2019, were retrospectively reviewed. Documentation of the following criteria was examined: pre-commencement pregnancy test, education education on the teratogenic potential of SV and/or the importance of avoiding unplanned pregnancy, information on contraception, and the rationale for prescribing SV over alternative treatments. Results Among the 3065 WOCP who had contact with SMHS during the study period, 51 women were newly prescribed SV and at risk of pregnancy. Twenty-one women (41%) had a recorded reason for prescribing SV over alternative treatments, four women (8%) underwent a pre-commencement pregnancy test, 10 women (20%) received information about the teratogenic potential of SV and/or the importance of avoiding unplanned pregnancy, and 21 women (41%) had documentation regarding contraception. Conclusion The study findings indicate heterogeneous and suboptimal documentation of specific risks associated with SV use in WOCP in SMHS. Interventions are needed to improve prescribing and documentation practices.