Vilazodone is a serotonin transporter (SERT) and a partial agonist of HT1A. It has been approved by food and drug administration of United States (US FDA) for the treatment of major depressive disorder (MDD) in adults. This agent is considered as a new class of drug “serotonin partial agonist and reuptake inhibitor (SPARI)” by the World Health Organization (WHO). The authors planned to review the drug by using the key word of “vilazodone” on different data base and synthesize a working theory regarding the mechanism of selective serotonin reuptake inhibitor (SSRI) mediated serotonergic neurotransmision. The review also focuses on 5-HT1A autoreceptors. Due to its novel mechanism of action, initially it gave hope to the clinicians and researchers as majority of depressive patients are partial responders or treatment resistant to previously available antidepressants. But later research works suggested that the vilazodone is not much different than the drug available in market. Its side effects were found to be lower than other antidepressant but higher than placebo. It can be concluded that more comparative research between vilazodone and other antidepressant is required in making better opinion about this drug