Phytochemical investigation of the roots of Delonix regia yielded six compounds. They were identified as, aliphatic alcohol; heptadecanol [1], two phenolic acids; vanillic acid [2] and p-hydroxy benzoic acid [3], a mixture of the ester isomers of the trans- and cis-ferulate glucopyranoside [4], one flavonol glycoside; Kampferol-3-O-α-L-arabinopyranoside [5] and one megastigmanes; (6R, 9S)-3-oxo-α-dihydro-ionyl-9-β-D-glucopyranoside (Blumenol C-O-β-D-glucopyranoside) [6]. Identification of these compounds was based on ESI-MS, 1D and 2D-NMR analysis. All six compounds are new to the constituents of genus Delonix. The isolated compounds (1-5) were evaluated for their cytotoxic activities against human promyelocytic leukemia HL-60 cells and human monocytic leukemia U937 cells. The antioxidant activities were also evaluated using 1, 1-diphenyl-2-picrylhydrazyl free radical (DPPH), assay method.