The synthesis and antimicrobial activity of 31 morpholinium chlorides, divided into five series depending on the substituents attached to the nitrogen atom, N-carboxyalkyl-morpholinium chlorides (la-e), N-carbalkoxymethyl-N-methyl-morpholinium chlorides (2a-f), N-carbethoxymethyl-N-alkyl-morpholinium chlorides (3a-g), N-carbalkoxymethyl-N-dodecyl-morpholinium chlorides (4a-f) and N-car-boxymethyl-N-alkyl-morpholinium chlorides (5a-g) is reported. The compounds investigated were tested for antimicrobial activity against Staphylococcus aureus, Escherichia coli, Proteus vulgaris, Pseudomonas aeruginosa, Candida albicans and Trichophyton menthagwphytes. The most active are compounds with a long N-alkyl group and with the substituent CH2COOCnH2n-1 (n = 8-16).