Introduction: Timed intercourse (TI) based on ovulation monitoring is an effective and common choice for treatment of infertility. However, TI related female sexual dysfunction remains to be elucidated. Method and Material: This was a prospective study and 105 infertile women were included using the Female Sexual Function Index (FSFI) to assess their sexual function in general sexual life (GSL) and TI cycle. Results: The mean age of the patients was 29.4 ± 3.4 years and the duration of infertility was 1.8 ± 0.5 years. The mean score of FSFI was 25.2 in GSL cycle and 24.5 in TI cycle (p = 0.008). Scores of 5 out of 6 domains of FSFI during GSL cycle were significantly higher than the counterparts during TI cycle. Female sexual function was related to stress, which mostly came from patients themselves and parents. The stronger the stress was, the more domains of FSFI were affected. Conclusion: Infertility is an important factor affecting female sexual function, especially TI condition reduced FSFI score in several domains, and this may be related to infertile stress.