Since the introduction of a nitro group into the 5 position conferred in vitro bacteriostatic activity against both Gram- positive and Gram-negative bacteria upon furan and its simple derivatives, the function of this group when placed in other heterocyclic ring systems analagous to furan was deemed of interest. Thiophene and pyrrole were chosen as representative heterocyclic systems; the nitro compounds of the acetyl derivatives prepared, and compared by accepted in vitro testing methods with the known antibacterially active 5-nitro-2-acetofurone. Also included for comparison were the non-nitrated compounds and the semicarbazones of both these and nitrated compounds. The effect of the introduction of the nitro group upon bacteriostatic activity is demonstrated. The thiophene derivatives follow the trend of the furan derivatives but to a lesser degree while the pyrrole compounds display substantially no activity.