We report the clinical case of a patient with obesity and an initial diagnosis of type 2 diabetes with poor beta-cell reserve, hospitalized for diabetic ketoacidosis. The evaluation of diabetic autoimmunity during the hospitalization led to the diagnosis of Latent Autoimmune Diabetes in Adults (LADA), with a subsequent adjustment of pharmacological therapy by initiating insulin with a basal-bolus regimen. During outpatient visits in the following months, the introduction of Metformin and the use of flash glucose monitoring (FSG) led to a progressive improvement in glycemic control. However, the almost replacement insulin therapy was associated with a significant weight gain. Consequently, an incretin-based drug was introduced in combination with basal insulin, which allowed for the maintenance of glycemic control within target range and a reversal of the weight gain trend up to the most recent visit. The previous suspension of insulin therapy, likely the precipitating event of the diabetic ketoacidosis, highlights the importance of an early diagnosis of LADA for a correct pharmacological management of the disease. The diagnosis itself may be often challenging and concomitant factors, such as obesity, may be misleading in the correct assessment of this pathology. Moreover, the phenotyping of the patient with LADA through the measurement of autoantibodies and the weight management have a key role to ensure a good management of the disease.