First and last mile connectivity of public transport hubs is a key component in promoting multi-modal travel. The Dutch train station operator (NS Stations) promotes the combination of bike and train by offering a train station-based round-trip bikesharing (SBRT) scheme, known as ‘OV-fiets’, located at train stations throughout the country. This scheme allows users to rent a bike to travel between train stations and their destination and vice versa. The round-trip nature of the SBRT makes it unique in comparison to widely applied one-way bikesharing schemes. Little is known about the determinants of demand for round-trip bikesharing, especially when being integrated into an existing PT scheme. This paper aims to fill this gap by identifying potential temporal and weather-related determinants for SBRT-rentals of the Dutch SBRT-system using multiple linear regression (MLR) and an in-depth analysis for selected stations. The results are compared with the findings of one-way bikesharing schemes. The results show that for hourly rentals in an SBRT-system, the highest explanatory power is attributed to the number of train travelers leaving the corresponding train station, followed by temporal and weather-related determinants. Furthermore, the magnitude of the correlation between the determinants and the hourly demand varies considerably across stations, depending on the underlying demand patterns.