Salmonella (S.) Typhimurium infection in pigs is a major source of human foodborne salmonellosis. Recently, the swine industry in Korea has been suffered from salmonellosis causing severe economic loss to farms. Organic acids have antibacterial activity which prevents bacteria from multiplying by reducing the pH in the gastrointestinal tract. The aim of the present study is to evaluate whether $Salstop^{(R)}$ mixed with organic acids is able to have influence on growth performance and whether it prevents against S. Typhimurium in weaning pigs. Four experimental treatments were examined: general diet added with 0.3% of $Salstop^{(R)}$ after S. Typhimurium ($1.0{ imes}10^{10}CFU/ml$) challenge, group A; commercial feed after Salmonella ($1.0{ imes}10^{10}CFU/ml$) challenge, group B; commercial feed and $Salstop^{(R)}$, group C; commercial feed, Group D. At the end of the study, no significant differences in daily body weight gain and feed intake were observed between groups treated with $Salstop^{(R)}$ and groups treated without, whereas feed conversion ratio (FCR) tended to be improved in groups treated with $Salstop^{(R)}$ between days 1 to 14. Serological and microbiological evolution of the infection were examined by ELISA and microbiological culture from serums and fecal samples, respectively. In groups that challenged by S. Typhimuriums, the group without $Salstop^{(R)}$ showed higher prevalence and bacterial shedding compared to the groups treated with $Salstop^{(R)}$. Our results suggest that the administration of $Salstop^{(R)}$ could be used to promote feed efficiency and to reduce the prevalence of salmonellosis in weaners.