Enuresis is one of the most frequent urinary symptoms in children. 80% suffer from primary enuresis nocturna. 20% have urinary incontinence with additional symptoms of frequency, urgency and daytime incontinence, which is also defined in children as overactive bladder in absence of urinary tract infections, neurological, anatomical or further local pathology (OAB in childhood). The underlying pathophysiology is a maturation arrest of the bladder control resulting in detrusor hyperactivity. In most of the cases the differentiation between enuresis and OAB is easily possible with non-invasive primary diagnostic procedures. Invasive diagnostic tools like video urodynamic studies may become necessary when first-line therapy fails. The treatment options comprise bladder training with timed voiding and drink protocols (urotherapy) as well as pharmacologic relaxation of detrusor instability by anticholinergic drugs.