While amenorrhea can be caused by a various reasons, hormonal disbalance and hyperprolactinemia, in particular, are frequent causes. Hyperprolactinemia is often seen among schizophrenic patients due to a D2 receptor blockade caused by antipsychotics. Risperidone is an atypical antipsychotic that has more pronounced serotonin antagonism compared to dopamine antagonism. However, risperidone has a high affinity for D2 receptor. Due to its blockade in the tubero-infundibular system, risperidone can produce a rise in prolactin. Data suggests that compared to other atypical antipsychotic drugs, risperidone may cause more frequent increases in prolactine levels. Interestingly, studies have shown that rates of hyperprolactinaemia are, in fact, also higher with risperidone than with FGA (50-100% compared to 40-90%). Finally, the relationship between doses of risperidone and prolactin levels has been demonstrated. Paliperidone Extended Release (ER), a new oral atypical antipsychotic (R076477, Invega; Johnson & Johnson Pharmaceuticals, L.L.C., Titusville, NJ), is an atypical antipsychotic that belongs to the chemical class of benzisoxazole derivatives. It is the major and active metabolite of risperidone (9-hydroxyrisperidone). Paliperidone is a centrally active dopamine D2 and serotonergic 5-HT2A antagonist, as demonstrated in both in vitro and in vivo animal and human studies. Since paliperidone is an active metabolite of risperidone, it would be reasonable to assume that paliperidone would have a similar side effect profile as risperidone since both raise prolactin levels. This report describes an adult woman treated by risperidone which induced amenorrhea. The amenorrhoea was then successfully subsided after the introduction of paliperidone.