Hager and Brudney (2004, 2005) developed a Net Benefits Index (NBI) to measure the performance of volunteer programmes. Their benchmarking tool scores an organisation's performance against six specific benefits and eight recognised challenges that organisations face in recruiting and managing volunteers. This article extends the NBI by demonstrating its use as an internal programme evaluation tool within two health non-profit organisations. By surveying all staff and volunteers (rather than relying on the organisational response from a single individual), the tool provides valuable insights into volunteer and staff attitudes about the volunteer programme. In addition to critiquing the NBI, this article highlights reasons for divergent scores between volunteers and staff and the improvements that can be made to a volunteer programme's effectiveness as a result of measurement.