A gynandromorph of a pierid butterfly, Eurema hecabe, caught at Mt. Tsukuba in Central Japan is described here. Wings were apparently bilaterally asymmetric, while the external and internal genitalia clearly showed the morphology and genotype of the female. The fact that this individual showed a female genotype excluded the possibility of incomplete feminization due to Wolbachia infection. Presence of a spermatophore in the bursa copulatrix and the difference in number of matured eggs between the right and left ovaries indicated that this gynandromorphic individual had copulated and oviposited in the field.