A method for microinjection was developed for the housefly, Musca domestica. Chorion membranes of freshly laid eggs were first removed with sodium hypochlorite (NaOCl). Dechorionated eggs were placed on double-sided Scotch tape, desiccated and covered with Halocarbon oil (Sigma). Posterior ends of the eggs were pierced with a fine glass needle for microinjection. Injected eggs were incubated at 25°C until hatching. Eggs dechorionated approximately 40 min after oviposition showed the highest hatching rate. Green food dye and suspended plasmid DNA constructs, included in the phosphate buffer, showed no harmful effects on embryonic development. Using the above procedure, an average of 75.0% of injected eggs survived to the first larval stadium. The technique described herein can be used for microinjection of various substances into the housefly.