Synthesis of some 4H-pyrido[1,2-a]pyrimidin-4-ones and assay of their antibacterial and antifungal activity are reported. Compounds 3a-e,g were prepared by reaction of substituted 2-chloromethyl-4H-pyrido[1,2-a]pyrimidin-4-ones 2a-c with suitable amines. These compounds and the previously obtained analogues 5a-o and 6a,b have been tested for their antimicrobial activity. All tested compounds were devoid of antimicrobial activity.