The aim of this study was to compare the efficacy of flower therapy for the treatment of anxiety in overweight or obese adults with that of a placebo. The authors examined improvement in sleep patterns, reduction in binge eating, and change in resting heart rate (RHR). This was a randomized, double-blind, placebo-controlled clinical trial with a parallel-group design and two arms. Clinical Research Unit, Medical School, São Paulo State University, Botucatu, SP, Brazil. The study included 40 participants in the placebo group and 41 in the intervention group. Participants were of both genders, from 20 to 59 years of age, overweight or obese, with moderate to high anxiety. The participants were divided into two random groups: one group was treated with Bach flower remedies (BFR) (bottles containing 30 mL of 30% hydro-brandy solution with two drops each of Impatiens, White Chestnut, Cherry Plum, Chicory, Crab Apple, and Pine), and the other group was given a placebo (same solution without BFR). The patients were instructed to orally ingest the solution by placing four drops directly in the mouth four times a day for 4 weeks. : The primary outcome was anxiety (State-Trait Anxiety Inventory [STAI]). Secondary outcomes were sleep (Pittsburgh Sleep Quality Index [PSQI]), binge eating (Binge Eating Scale [BES]), and RHR (electrocardiogram). Multivariate analysis showed significant reductions in scores for the following variables in the intervention group when compared with the placebo group: STAI (β = -0.190;  < 0.001), PSQI (β = -0.160;  = 0.027), BES (β = -0.226;  = 0.001), and RHR (β = -0.07;  = 0.003). The anxiety symptoms, binge eating, and RHRs of the individuals treated with flower therapy decreased, and their sleep patterns improved when compared with those treated with the placebo. Registered at the Brazilian Registry of Clinical Trials (no. RBR-47-kfxh).