Orthostatic proteinuria, also known as postural proteinuria, is a condition where an abnormally large amount of protein is excreted in the urine when the patient is in an upright position and normal protein excretion in the supine position. It affects approximately 2 to 5% of adolescents and is uncommon after 30 years of age. Orthostatic proteinuria is a benign condition. Hence, a proper diagnosis of orthostatic proteinuria is important in clinical practice to ensure that no unnecessary intervention, such as a renal biopsy, is carried out. Proposed mechanisms include some possibilities, such as it is a normal variant, there is a subtle glomerular abnormality, it is an exaggerated hemodynamic response, and it is due to a left renal vein entrapment. People with lower BMI show persistent orthostatic proteinuria as opposed to those with higher BMI, and the space between the superior mesenteric artery and aorta varies according to BMI. This article will discuss the etiology, epidemiology, pathophysiology, evaluation, and management of orthostatic proteinuria in greater detail.