1-Thia-4-benzyl-4-azspiro[4,4]nonan-3-one (2a) and/or 1-thia-4-benzyl-4-azaspiro[4,5]decan-3-one (2b) reacted with 4-arylidene-3-methylpyrazolin-5-ones (1a-f) in a mixture of ethanol/pyridine at reflux temperature to give spirothiazolopyranopyrazoles (3a-l) in one flask. The fusion of compounds 1a-f with 2a and/or 2b in the presence of ammonium acetate afforded spirothiazolodihydropyridinopyrazole derivatives (4a-l) in good yields. Also the reaction of compounds 1a-f with 2a and/or 2b with phosphorus pentasulfide in pyridine at reflux temperature yielded the spirothiazolothiopyranopyrazoles (5a-l). All the synthesized spirohetenxyclic derivatives were identified by conventional methods (IR, ¹H-NMR) and elemental analyses. All the prepared compounds were tested for their antimicrobial activities in comparison with tetracycline as a reference compound.