Since the Korean pronoun system does not specify gender indication, Korean speakers of English tend to have difficulties when they use English pronouns. This paper explores how absence of obligatory gender marking in Korean affects gender errors in the production of English. Gender pronoun errors made by Korean learners of English were analyzed using recordings of English conversations of seven Korean subjects. Findings of this study revealed that Korean English learners struggled with the use of gender pronouns due to differences in gender pronoun systems between Korean and English. Both gender-neutrality and pro-drop practices do not require Korean speakers to pay close attention to gender factors when using pronouns in their native language, resulting in native language interference. Considering that the Korean language lacks specific gender orientation in its usage of pronouns whereas English requires clear gender specification, findings of this study imply that native language gender concept can influence second language use.