Obesity is a major public health issue and primary care practitioners are well placed to opportunistically raise the issue of overweight or obesity with their patients. This study investigated the prevalence of weight discussion in primary care consultations with overweight and obese patients, in a practice in Fife, Scotland, and described weight-related communication using video analysis. Weight was raised in 25% of consultations with overweight and obese patients. GPs initiated weight discussion more often than patients however these attempts were often blocked by patients. Weight-related outcomes were more common when patients initiated the weight discussion. This study confirms the potential of video analysis for understanding primary care weight discussion. It also suggests that GPs may benefit from a communication based intervention to tackle patient blocking behaviours and contributes to the evidence suggesting that interventions targeted to increase the prevalence of weight related discussions with their patients are needed.