The objective of this study was to investigate Grade of Membership analysis (GoM) as a means of profiling the practice styles of individual physicians. GoM uses maximum likelihood techniques to estimate occurrences of management items that define unique practice styles. It also provides statistical estimates (grade of membership coefficients) of how well each individual physician's practice fits the identified styles. Data sources were responses to a mailed survey asking 814 physicians to select from predetermined management options in three scenarios depicting patients with acute low back pain. Four distinct types of practice style were identified: watchful waiting; investigative; guideline based; and physiotherapy focused. Most physicians were characterized by high grades of membership in the two profiles that most closely matched existing guidelines for the management of acute low back pain. GoM successfully identified characteristic practice styles, and the GoM coefficients obtained provided descriptions of individual management approaches. GoM is data driven and less subject to judgment than opinion-based measures of performance. It has several potential applications in identifying physicians for whom some form of intervention would be beneficial.