There are some conflicting results regarding the benefit of adjunctive therapy with statins for severity of negative symptoms in schizophrenia. This study aimed to verify whether statins use for adjunctive therapy was indeed beneficial to improve psychiatric symptoms in schizophrenia. The data were from CENTRAL, PubMed, Embase and MEDLINE. The Boolean search term used for the electronic database search was (statin OR simvastatin OR atorvastatin OR fluvastatin OR lovastatin OR mevastatin OR pitavastatin OR pravastatin OR rosuvastatin OR cerivastatin) and (schizophrenia OR schizoaffective disorder OR psychosis). Inclusion criteria were the following: RCTs, the adult schizophrenia patients, received antipsychotics plus statins or placebo, and the PANSS or SANS scores. Exclusion criteria were as follows: no data reported and multiple reports of the same study. A meta-analysis was used to compare psychiatric symptoms in schizophrenia patients with or without statins adjunctive therapy. The 6 RCTs included in the analysis represented 339 participants (169 in treatment group versus 170 in placebo group). A test for overall effect demonstrated that the PANSS positive scale and negative scale significantly reduced in participants receiving compliant with statins. Our meta-analyses first clarified that adjunctive therapy with statins could improve psychiatric symptoms, either negative symptoms or positive symptoms.