A cross-sectional survey was conducted of USA clinicians prior to participation in an Internet-based educational programme on herbs and dietary supplements. The 537 participants included 111 physicians (MDs), 30 advanced practice nurses (RNs), 46 pharmacists (PharmDs) and 350 dieticians (RDs). In addition to demographic information, participants were asked about their knowledge, attitudes, and practices related to herbs and other dietary supplements. Most participants were involved in direct patient care (85%), in practice or on faculty (84%), and from outside our local institutions (76%); 66% reported receiving professional education about herbs and other dietary supplements in the past year. There were statistically significant differences between professional groups, with RDs scoring better than others, but even their average scores were less than 60% of possible. The average score on knowledge questions was 10/20; the average confidence score was 4 out of 10 possible, and the average communication score was 1.4 out of 4 possible. Most respondents knew the most common clinical uses of echinacea and St John’s wort, and felt confident that they knew more than their colleagues about herbs and dietary supplements. Key deficits were in knowledge about adverse effects, confidence in reporting side-effects, routinely communicating with patients about herbs and dietary supplements, and recording herbs and dietary supplements information in the medical record.