Face fly, Musca autumnalis DeGeer, continues as a major pest of cattle in New Jersey. In 1962 tests were made on full herds in Somerset and Hunterdon Counties, and on smaller groups of animals within herds at Beemerville in Sussex County on all of which face flies were counted on heads and bodies of 20 animals at least once each weekday unless the group contained less than 20 animals, in which case all were counted. Results were evaluated by comparing treated and untreated herds on the same day and calculating the average per cent reduction on the treated animals. Ciodrin® (previously known as Shell 4294, dimethyl 2-alpha methylbenzyloxycarbonyl-1-methylvinyl phosphate) was considerably superior to other materials and in nearly every case reduced face flies to a level where animals were reasonably free of annoyance, that is, with less than 10 flies per face. Ciodrin provided this level of protection when it was applied as indicated three times a week at the following dosages: 2% at 1 pint and at one-fourth pint per animal, using a knapsack sprayer, and 4.0 and 0.4% applied 5 ml. to the face plus 5 ml. to the back and sides, using a face fly sprayer (Hudson Hydragun as modified by Matthysse). Sugar was added to these spray mixtures at the rate of 2 pounds per 10 gallons, with the knapsack sprayer and 3 oz. per gallon with the face fly sprayer. Ciodrin reduced flies on the faces of the animals from 55% to 89% on the day of treatment and from 45% to 93% the day following treatment. Higher reductions were obtained on the bodies even though total flies were more numerous. After a series of treatments was completed, face flies remained at levels of 10 or less flies per face and body (20 per animal) for 3 to 10 days. When applied weekly at the rate of 1 quart per animal, 0.3% Ciodrin plus sugar gave satisfactory results for an entire week. General Chemical 4072 (2-chloro-l-(2, 4-dichloropenyl)vinyl diethyl phosphate), Pyramat® (2-n-propyl-4-methylpyrimidyl-(6)-dimethylcarbamate), and Dimetilan® (l-dimethylcarbamyl-5-methyl-3-pyrazolyl dimethylcarbamate) gave promising results. Inferior to these insecticides were the daily application of 0.5% DDVP plus sugar as now recommended, diazinon dust, a formulation of 7.5% pyrethrins and 75% piperonyl butoxide, an unrefined pyrethrum extract, 5% Sevin® (1-naphthyl N-methyl. carbamate) plus 50% Crag Fly Repellent® (butoxy polypropyleneglyeol), Sumithion® (O, O-dimethyl O-4-nitro-m-tolyl phosphorothioate), and Famophos® (O, O-dimethyl, O, p-(dimethylsulfamoyl) phenyl phosphorothioate). Applications by pressure sprays, face wipes, or automatic sprayers were unsatisfactory except for a limited period.