Considerable numbers of pregnant women do not understand the correct way to use seatbelts; thus, they are inappropriately restrained when wearing seatbelts. To improve appropriate seatbelt wearing by pregnant women vehicle passengers, we examined their use by pregnant women drivers and the independent factors influencing appropriate use. We undertook a cross-sectional survey of 1,000 pregnant women in Shiga Prefecture, Japan. Among 774 returned questionnaires, we analysed those of 680 pregnant women who always wore a seatbelt. The mean participant age was 31.4 ± 5.0 years and mean gestational age 26.2 ± 8.2 weeks; 97.7% of subjects always wore a seatbelt; 86.9% wore a seatbelt correctly and 13.1% incorrectly. Multivariate analysis indicated that receiving information about correct seatbelt use (odds ratio, 2.25; P < 0.005) and gestational age (odds ratio, 1.06; P < 0.001) were significant independent factors for correct seatbelt use. Providing information about correct seatbelt use during the early term is required for pregnant women to protect both the mother and fetus.