Background and objectives The optimal role of general practice in population weight management remains unclear. The aim of this mixed-methods study was to test the feasibility of routinely weighing all adult patients attending their general practice as an intervention to aid weight management in clinical practice. Methods Consenting patients in six general practices were weighed at each presentation over a 12-month period. Data were analysed using linear mixed growth models. Participants' interviews at the completion of the study were thematically analysed. Results The overall weight loss in patients who completed the study (n = 217) was 0.51 kg (P = 0.26; not significant); in patients who were obese (n = 106) there was a greater weight loss of 1.79 kg (P = 0.04). Patients were receptive to the intervention; however, there was disruption to clinical workflow. Discussion Routinely weighing adult patients in general practice is feasible, requires resources and may be associated with weight loss in patients who are obese. Further research is required to inform support for implementation within practices.