Personal health records (PHRs) are important for improving patient care. An important prerequisite to realize benefits of PHR use is patient recruitment. To understand clinic barriers to adoption, we used Rogers' Diffusion of Innovations theory to frame an examination of clinic staff perceptions of a new PHR and perceptions of likely patient portal users. Clinic staff reported many relative advantages and observable benefits of the PHR but also some distinct problems. Attributions about potential patient users included demographic, computer use, and personality characteristics staff expected in likely users. Analysis of patient survey data of early adopters compared to non-users revealed discrepancies between clinic staff expectations and early adopters' self-reports. Implications for improving adoption of PHRs include ensuring compatibility with existing systems and avoiding recruitment biases.