Background Screening for sexually transmitted infection (STI) especially HIV as early detection and treatment have been financially supported under the Thai Universal Coverage (UC) scheme since 2009 (THB140 for HIV). However, there has been no evidence-based strategic risk-based implementation nor economic evaluation whereas husbands who accompanied the pregnant women are likely to have lower risk than those who did not come along. This study is aimed to explore husband’s willingness-to-pay (WTP) for his HIV and syphilis screenings at ANC. Methods A survey of 200 randomly selected husbands of pregnant women was conducted at King Chulalongkorn Memorial Hospital from April to June 2018. A pilot study using an open-ended question was conducted to estimate the mean and standard deviation of WTP for HIV and syphilis screenings. Then, two contingent valuation methods (bidding and payment scale) were performed for the final WTP assessments, using the mean WTP identified from the pilot study as a starting WTP with 1⁄4 SD step up/down. Multivariate linear regression was performed to explore potential determinants of the price that the husbands are willing to pay. Results During the study period, 597 pregnant women received their first ANC. Of 368 accompanying husbands, 200 were enrolled in the study. Their median age was 31 (IQR 27-36) years old and 67% had a first child. Eighty-eight percent of the participants were willing to test for STIs. Based on the bidding method, WTP for HIV and syphilis tests were US$14.5 (IQR 12.4-14.5) and US$9.7 (IQR 10-12), respectively. The payment scale method suggested approximately three-quarter of the price. Expecting the first child and higher education were associated with a higher price (P <0.01). Conclusions The husbands presented at antenatal care clinic are willing to pay at least two times the cost of the STI test. The financial support to promote STI screenings should be reconsidered to cover other groups with higher sexual behavior risks and less willingness-to- pay.