Weight-gain in psychiatric populations is a common clinical challenge. Many patients suffering from mental disorders, when exposed to psychotropic medications, gain significant weight with or without other side-effects. In addition to reducing the patients' willingness to comply with treatment, this weight-gain may create added psychological or physiological problems that need to be addressed. Thus, it is critical that clinicians take precautions to monitor and control weight-gain and take into account and treat all problems facing an individual. In this review, we examine some of the key issues surrounding weight-gain in individuals suffering from mental disorders for contemporary practitioners in community clinics. We describe some factors known to make certain patients more susceptible to treatment-induced weight-gain and mechanisms implicated in this process. We also highlight a few psychological and pharmacological interventions that have proven effective in weight management. Importantly, we provide critical steps for management and prevention of weight-gain and related issues in the clinical practice of psychopharmacology.