Abstract The first reported 1, 3-dipolar cycloaddition of 2-styrylchromones with diazomethane afforded 4-aryl-3-(2-chromonyl)-2-pyrazolines. However, 3-aryl-4-(2- chromonyl)-1-pyrazolines have been also found as minor products of this reaction. These two series of pyrazolines have been fully characterized.