The objective of this study was to assess the level of preparedness of rural health unit nurses in responding to patients with suspected sexually transmitted infections (STIs) in Lanao Del Sur Province, Philippines. A total of 147 nurses participated in the study from 39 rural health unit facilities using Cochran formula. The study used a self-administered questionnaire (SAQ) adapted from the Philippines' Department of Health (DOH) Manual for Training in Care and Prevention of STIs. The study revealed that the rural health unit (RHU) health care facilities and services, supplies and equipment, and training and seminars for STIs program were inadequate as perceived by rural health unit nurses. Furthermore, the result showed that the rural health unit (RHU) nurse respondents perceived themselves to be very prepared (x̅ =21.30, SD± 2.36) in responding to patients with suspected STIs. Specifically, rural health nurses were very prepared in terms of attitude and behavior (x̅ =35.9, SD± 3.61), communication (x̅ =18.8, SD± 1.81), health assessment (x̅ =18.6, SD± 2.11), prevention of transmission (x̅ =18.7, SD± 1.95), contact tracing (x̅ =17.2, SD± 2.47), and confidentiality (x̅ =18.6, SD± 2.22). The study revealed a significant relationship between demographic profile and the perceived level of preparedness. The study concluded that rural health nurses are very prepared in responding to sexually transmitted infections cases.