A series of trifluoromethyl-substituted hexahydropyrimidine derivatives were efficiently synthesized in excellent yields via one-pot three-component reaction of aromatic aldehydes, ethyl trifluoroacetoacetate and thiourea(urea) in presence of p-toluenesulfonic acid under solvent-free conditions at room temperature by grinding. The present method does not involve any hazardous organic solvent and has proven to be simple, efficient, environmentally benign and cost-effective compared with the classical synthetic methods. These compounds were screened for their antibacterial activities against Escherichia coli and Bacillus thuringiensis and found to exhibit remarkably better antibacterial activities than the control drug.