BackgroundNosocomial infections are one of the main causes of mortality and morbidity in hospitals, especially in intensive care units (ICUs).ObjectiveThe aim of this study was to examine the impact of garlic tablets on nosocomial infections in hospitalized patients in intensive care units.MethodsThis clinical trial was carried out on 94 patients, admitted to the intensive care units in Kashani and Al-Zahra hospitals from January 21, 2014 to December 20, 2014. Firstly, the patients were randomly selected by simple sampling, then they were assigned into case and control groups. The case group administered one 400 mg garlic tablet daily for 6 days and the control group received placebo. During the study, inflammatory blood factors and infection occurrence in the two groups were compared. The Data were analyzed by SPSS software version 22 through descriptive tests such as independent t-test, Chi-square test, ANOVA and exact Fisher test for the analyses of primary and secondary outcomes.ResultsDuring the study period, 78 cases of intravenous catheter tip were sent to laboratory for culture, of which, 37 cases were in the intervention group and 41 in the control group. Culture results of Catheter tips was positive in 5 cases and all five cases were in the control group. Frequency distribution of catheter tip culture was significantly higher in the control group than that of the intervention group (p=0.03).ConclusionBased on the results of our study, in people with weakened immune systems and in people with high incidence of opportunistic infections, it is necessary to strengthen their body’s immune system stimulants before dealing with these infectious agents, and cause decrease in the diseases insusceptible people. It was suggested that garlic supplementation has shown to be effective in patients admitted to ICU, who are highly susceptible to nosocomial infection, and it can be used for the prevention of septicemia and urinary tract infections. However, further research with larger sample size is needed.Trial registrationThe trial was registered at the Iranian Registry of Clinical Trials (http://www.irct.ir) with the Irct ID: IRCT207406156480N6.FundingShahrekord University of Medical Sciences financially supported this research.