Enhanced Recovery After Surgery (ERAS) programs include multiple perioperative care elements, which when implemented together are designed to improve recovery after surgery with subsequent reduction in hospital length of stay (LOS). The aim of this study is to examine the impact of ERAS protocol compliance on LOS in patients undergoing advanced ovarian cancer surgery within the context of a randomized clinical trial. Patients were enrolled in a prospective, consecutive, interventional randomized clinical trial between June 2014 and March 2018. Women with either suspected or confirmed advanced ovarian cancer with International Federation of Gynecology and Obstetrics (FIGO) stages IIB-IVA and recurrent ovarian cancer, who underwent cytoreduction surgery, were randomly assigned to either a conventional management (CM) protocol or an ERAS protocol. Demographic items, preoperative clinical data, and surgical characteristics of patients were recorded, as were LOS and ERAS protocol compliance. Negative binomial regression was used to model the relation between length of stay and ERAS protocol compliance. We included 49 patients in the CM group and 50 patients in the ERAS group. The overall rate of ERAS compliance was 92%. We observed that increasing ERAS protocol compliance was associated with shorter median LOS, and in patients who underwent higher complex surgeries, the length of stay reduction was greater. This study identifies a correlation between increasing ERAS protocol compliance and decreasing LOS in ovarian cancer surgery. This finding underlines the necessity to implement as many ERAS protocol elements as possible to achieve optimal clinical outcome improvements.