Generally, hysteroscopy is not appropriate for pregnant women without an indication. What if a patient undergoes hysteroscopy accidentally during the early gestational period? We here report a rare case of a woman who continued pregnancy after a diagnostic hysteroscopy was performed in early pregnancy and delivered a healthy baby. The patient had a history of infertility and oligomenorrhea, probably due to a previous induced abortion. A hysteroscopy was performed after the end of her "menstruation" for assessment of her uterine cavity. Early pregnancy, instead of the expected intrauterine adhesions, was suspected, and the procedure was immediately ceased. Subsequent tests confirmed the diagnosis of pregnancy. She had a fullterm delivery by elective caesarean section. The success of this case was attributed to the use of vaginoscopic techniques in hysteroscopy and correct judgment and decision-making during the procedure. This case report provides some useful methods and experience that might be helpful when a similar situation occurs in clinical practice.