Zika virus (ZIKV) infection is a public health problem in the Americas. We assessed ZIKV knowledge, attitudes, and future ZIKV vaccine intent among medical students. In this cross-sectional study, a convenience sample of medical students in San José, Costa Rica, were surveyed to assess knowledge, attitudes, vaccine intent, and sources of information about ZIKV. Knowledge and attitude scores were calculated. Factors associated with vaccine intent were determined by bivariate analysis using a chi-square test. Of 468 participants surveyed, majority were females (299, 63.8%) and lived in urban areas (411, 87%). The participant mean knowledge score was 12.2 (SD: 3.65) out of a possible 20. Students residing in suburban or rural areas (odds ratio [OR]: 0.432; CI: 0.24-0.78), first- or second-year students (OR: 0.423; CI: 0.27-0.67), and aged < 20 years (OR: 0.586; CI: 0.36-0.97) had significantly lower knowledge scores. The participant mean attitude score was 30.2 (SD: 4.76) on a scale of 13-65, with lower numbers indicating a concern for ZIKV severity. A majority of the participants indicated they would be likely or extremely likely to receive a ZIKV vaccine (420, 89.7%) and recommend the vaccine to their patients (439, 93.8%). Vaccine intent was not influenced by demographics, total knowledge, and attitude scores. Students (388, 83%) identified the Internet as their primary source of ZIKV information. A majority of students demonstrated a positive attitude toward ZIKV and willingness to accept and recommend a vaccine. Low knowledge scores underscore the need for ZIKV education, especially in the early years of medical school. Use of the Internet should be considered in dissemination of ZIKV education.