A series of (E)-1-(4-fluorophenyl)-3-substitutedphenylprop-2-en-1-one (3-7) were ultrasonically prepared by the reaction of 4-fluoroacetophenone with different aromatic aldehydes in the presence of alkali . Reaction of the prepared chalcones (3-7) with 3,4,5-trimethoxybenzohydrazide (8) afforded the corresponding substituted pyrazoline (9-13). Ultrasonic irradiation method provides several advantages over current reaction methodologies, including a simple work-up procedure, shorter reaction times and good yields. All the prepared compounds have been characterized by FT-IR and 1H-NMR spectra. These compounds were screened for their antifungal activity using disc diffusion method. Compound 10 and 11 was found to exhibit the most potent in-vitro anti-fungal activity with against all the fungal strains.