A series of new 2-phenylethenylbenzothiazolium salts substituted by cyclic amines has been prepared by the condensation of 2-methyl benzothiazolium bromide with substituted benzaldehydes. The nucleophilic substitution of 4-fluorobenzaldehyde with appropriate cyclic amines has been used to obtain the starting benzaldehydes. The compounds with saturated cycloamino substituents have shown enhanced activity against Euglena and some derivatives with piperazine substituent were active against Gram positive bacteria.