Marigold flower (Tagetes erecta L.) produces lutein compounds which present biological activities such as antioxidant, antiinflammatory, antimutagenicity, and immunomodulatory effects. The study was to investigate the antioxidant activity of the lutein of T. erecta L. and the effect of lutein on the activity and phagocytic capacity of macrophage cells. The antioxidant screening was carried out using diphenyl picrylhydrazyl (DPPH), 2,2′-and-bis(3-ethylbenzothiazoline-6-sulphonic acid (ABTS) radical scavenging assay with serial concentrations and ferric-reducing antioxidant power (FRAP) method. For the observation of activity and phagocytic capacity of peritoneal macrophages, twenty-eight mice were used and divided into seven groups each comprising four replicates, i.e., Group (I) normal controls, mice were untreated (II) a negative control, mice were induced by Staphylococcus aureus (III) positive control, mice were induced by S. aureus and treatment of meniran extract (Phyllanthus niruri). The treatment group (IV-VII) mice were induced by S. aureus and treated crude lutein, respectively: 0.15 mg, 0.30 mg, 0.60 mg, and 0.90 mg. 20 g−1 of body weight. The lutein extracted from T. erecta shows an antioxidant activity against DPPH radical with an IC50 value of 53.58 μg.ml−1, while the antioxidant activity against ABTS has an IC50 value of 72.91 μg.ml−1. The antioxidant activity test results by the FRAP method at each lutein concentrations of 10, 25, 50, and 75 ppm were obtained respectively of 33, 88, 185.5, and 288.5 μmol Fe2+/g extract. The data were analyzed using one-way ANOVA and Duncan’s multiple range test (DMRT) after. The phagocytic activity was 45.5%; 54.75%; 57.50% and 67.0%, respectively, while the phagocytic capacity values were 355; 519; 611 and 767 S. aureus bacterial cells per 50 macrophage cells. The lutein from marigolds (T. erecta L.) is capable of scavenging free radicals and reducing oxidants. Lutein can increase the activity and capacity of phagocytic of peritoneum macrophage cells in mice.