Abstarct: We have described one-pot, solvent-free, rapid and efficient method for the synthesis of 1H-pyrazolo[1,2-b]phthalazine-5,10-dione derivatives via caffeine catalyzed reaction of aromatic aldehyde, malononitrile and phthalhydrazide at 100 oC. This method offers several advantages such as milder reaction condition, shorter reaction time, cleaner reaction, green and reusability of the catalyst, and high reaction yield.