This study investigates mahogany carpel ash as cement replacement at five different design mixtures: 20%, 40%, 60%, 80% and 100% mahogany carpel ash composition. Specimens without mahogany carpel ash were also prepared to serve as the control specimens for this study. The mortar specimens were tested for compressive strengths at curing age of 3 days, 7 days and 28 days. The characteristics of the ash were also determined to understand the physical and chemical contents of the ash. Results revealed that the use of 20% mahogany carpel ash cement replacement was able to meet the American Society for Testing and Materials (ASTM) C270 minimum strength requirement for Type M mortar. The 40% and 60% cement replacement met the minimum standards for Type N mortar and the 80% cement replacement met the minimum standards for Type O mortar. These findings provided information that may be useful to further conduct specific studies to enhance the utilization of mahogany carpel for concrete technology and the construction industry.