Adolescent suicide is a pressing concern in Guyana, a low-to middle-income country in South America with the highest adolescent suicide rate globally. Gatekeeper trainings for suicide prevention conducted in high-income countries have been found to increase knowledge of suicide prevention, increase referrals of at-risk youth, and reduce stigma toward help-seeking for suicidality. The current study sought to engage in a pilot examination of the effectiveness, acceptability, and feasibility of a culturally informed gatekeeper training suicide prevention program for Guyanese youth. Secondary school teachers and staff (N = 16) were trained in a culturally informed, evidence-based gatekeeper suicide prevention program. Mixed methods analyses revealed significant increases in knowledge of suicide prevention, as well as decreases in rigid or judgmental attitudes toward suicide post-training among secondary school teachers and staff. Further, results indicated that participants deemed the program culturally acceptable and feasible for use in the school setting. Findings have implications for the delivery and implementation of culturally informed gatekeeper training programs for suicide prevention in low-to middle-income countries.