Photochemical treatment is one of the pathogen inactivation method to treat plasma, part of a proactive approach used for blood and blood component safety. Three photochemical treatments that have been used were methylene blue, riboflavin and psoralen treatment. This study was done on Fresh Frozen Plasma (FFP) to evaluate the treatment effects of psoralen, methylene blue and riboflavin on coagulation factors level. Methods: FFP was collected from apheresis plasma units and kept at 22oC to 24oC. A sum of 90 apheresis plasma units and segments were used, separated from each bag and a part used as controls, placed in a -30oC freezer for storage, thawed, and coagulation proteins function was evaluated before and after treatment, at immediate, 30 days and 270 days storage. Results: Significant differences in fibrinogen and coagulation factor levels between before and after treatment with methylene blue, psoralen and riboflavin. However, most of the mean values in treated plasma were within reference ranges. Methylene blue treated FFP showed the lowest changes in fibrinogen and other coagulation factors level whilst riboflavin treated FFP demonstrated the highest changes in coagulation proteins concentrations especially for fibrinogen, FV, FVIII, FIX and FXII. However, FXIII showed the best recovery for all three photochemical methods with reduction level of 3% to 8% compared to pre-treatment. Storage time comparison of immediate, 30 days and 270 days was inconclusive. Conclusion: The coagulation proteins in psoralen treated FFP and MB-FFP were adequately preserved, where MB-FFP showed better preservation than other two photochemical treatments.