Synthesis of a series of fourteen novel 2,2',4',5'-tetra-substituted-1,2,2',4'-tetrahydro-4H-spiro[isoquinoline-3,3'-pyrazol]-4-ones was accomplished in good yield by regio and steroselective 1,3-dipolar cycloaddition of α-chloro-aryliden-phenylhydrazones with (3Z)-3-(arylidene)-2-phenyl-2,3-dihydroisoquinolin-4(1H)-ones 4-8 with dipolarophiles [(3Z)-2-phenyl-3-(p-R 1 -phenyl)-2,3-dihydroisoquinolin-4(1H)-ones] 1-3. The structure of the isolated products 9-22 was established through different spectroscopic techniques. X-ray crystal structure analysis of one of the products confirms the structure and the selective region and stereochemistry of this cycloaddition. Their antitubercular activity is evaluated.