7-Methyltetrazolo[1,5-a]quinoline-4-carbaldehyde (1) was reacted with thiosemicarbazide to give the appropriate thiosemicarbazone (2). Compound (2) was reacted with different α-halocarbonyl compounds such as phenacyl bromide, hydrazonoyl chlorides and α-chloroacetic acid to afford thiazoles (4), aryldiazenylthiazoles (6), and thiazolidin-4-one (8), respectively. A series of 7-methyltetrazolo[1,5-a]quinoline derivatives, such as 2-imino-2H-chromene (11), arylacrylohydrazides (13), (15) and (17) and (heteroarylethylidene) acrylohydrazides (19), (21) and (23) has been synthesized. The structures of the newly synthesized compounds have been confirmed by spectral and elemental analyses.