1,3-Dipolar cycloaddition to o-quinodimethanes has been observed for the first time in the reaction of pyrazole and isoxazole o-quinodimethanes 4–6 with the stable nitrileoxides 7 and 8. The products, dispiroisoxazolines 9–14, were isolated in moderate yields. In all cases the “anti” addition stereoisomers 9a–14a were formed, as was established by X-ray crystallographic analysis on 13a and 14a, whereas