The aim of this study was to analyze the individual and combined antimicrobial effects of avocado seed (Persea americana) and ketepeng cina leaf (Cassia alata) methanol extracts against Staphylococcus epidermidis using the Kirby Bauer assay. Variations in the proportions of P. americana to C. alata (A: K) extracts were 4: 0 mg/mL, 8: 0 mg/mL, 12: 0 mg/mL, 0: 4 mg/mL, 0: 8 mg/mL, 0: 12 mg/mL, 4: 4 mg/mL, 4: 8 mg/mL, 4: 12 mg/mL, 8: 4 mg/mL, and 12: 4 mg/mL respectively, and the tests were executed in four replicates. The positive controls used were Clindamycin and Chloramphenicol, while the negative was DMSO. After 24 hours of incubation, zones of inhibition were exhibited by the experimental group and positive control, but not by the negative test. The largest diameters from the methanol extract of P. americana seeds and C. alata leaves singly at strengths of 12 mg/mL were 5.96 mm and 9 mm, while the mixture at various concentrations showed the pattern of growth organism as an indifferent (additive) effect.