The dopamine system is important for micturition, and dopamine D2 receptors are involved in the facilitation of micturition.1 Amisulpiride, a dopamine D2 receptor antagonist,2 might inhibit voiding ability because of the inhibition of D2 receptor-related micturition facilitation; 10% of urinary retention is associated with concomitant medications, including antipsychotics.3 Antipsychotics, such as clozapine, olanzapine, and haloperidol, have also been suggested to influence the inter-contraction interval, bladder capacity, bladder residual volume, micturition volume, external urethral sphincter function, and resting pressure of the bladder through the dopamine D2 antagonism and accompanying antimuscarinic effects.4–6 Ziprasidone is also reported to cause urinary hesitancy and urinary retention.7 In this case, urinary retention appeared after 4 years of amisulpiride use, which suggested that this patient might have changes of dopamine-receptor sensitivity and organic deteriorations of the urological system. The physiological evidence from the urodynamic study also supported this hypothesis. The urinary difficulties after treatment with paliperidone might be related to alpha1 antagonism, alpha2 antagonism, lack of anticholinergic effects, and serotonin 5HT7 antagonism.8–10 Although paliperidone also has D2 antagonism effects, paliperidone enters the brain less because of greater affinity for the P-glycoprotein,8 which might explain the relief of voiding dysfunction in this patient after using paliperidone. 5HT7 antagonism effects can also help relieve anxiety.11 Although amisulpiride also has 5HT7 antagonism effects, without anticholinergic effects, amisulpiride still lacks alpha-adrenergic antagonism, and its D2 antagonism might be higher than paliperidone because of the P-glycoprotein effects. These literature reviews may help us explain why this patient improved after using paliperidone, and this case report might provide us a clue about the urological side effects of atypical antipsychotics and the possible management of this issue.