The study aimed to investigate differences in the prevalence of gynecological healthcare service utilization in 12 ethnic minority groups and associated socio-demographic correlates with gynecological healthcare service utilization in Vietnam. Based on the national survey on healthcare utilization among 6912 people in 12 ethnic minorities, 900 women aged 21–49 years were included in the final analysis. Prevalence of gynecological healthcare service utilization in 12 ethnic minority groups was measured, based on the question “Have you ever used any gynecological healthcare services?” Socio-demographic characteristics including region, ethnicity, age, marital status, literacy level, education level, languages spoken, occupation, religion, household economy status, using contraception, and distance to the nearest healthcare facility were examined. The association between gynecological healthcare service utilization and socio-demographic characteristics was assessed by using logistic regression. The results showed that the prevalence of gynecological healthcare service utilization was 62.0% (95% CI: 58.7–65.2%), which ranged from 36.5 (Mnong) to 87.7% (Bru Van Kieu). Bru Van Kieu women had significantly higher odds of gynecological healthcare service utilization (OR = 9.42, 95% CI = 3.71–23.91), compared to those in Khmer ethnicity. Besides, Ba Na, Cham Ninh Thuan, and Dao women also had significantly higher odds of gynecological healthcare service utilization (Ba Na: OR = 5.73, 95% CI = 2.15–15.26; Cham Ninh Thuan: OR = 4.24, 95% CI = 1.79–10.06; Dao: OR = 3.43, 95% CI = 1.49–7.90), compared to those in Khmer ethnicity. Getting married, being older, being not poor, and using contraception had significantly higher odds of using gynecological healthcare services. Health education specialists and healthcare workers should be aware of these issues so that they can provide appropriate gynecological healthcare services and ensure high coverage of routine gynecological exams in ethnic minority women in reproductive age.