The emergence of multi-resistant bacteria especially Staphylococcus aureus (S. aureus) and Pseudomonas aeruginosa (P. aeroginosa) to antibiotics is one of the health concern issues of the recent decades. Among the possible resolutions of this concern, the secondary metabolites of medicinal plants seem to be privileged. Carried out in this context this work is based on the phytochemical study and the antibacterial activity of leaves extracts of Vernonia colorata (Willd.) Drake on resistant S. aureus to methicillin and P. aeruginosa resistant to ceftazidime and imipenem. The phytochemical assessment proved that the leaves of Vernonia colorata, harvested in Yamoussoukro (Côte d'Ivoire), contain flavonoids, saponins, tannins, steroids, terpenoids and cardiac glycosides. The values of minimum inhibitory concentration (MIC) and those of the minimal bactericidal concentration (MBC) of ethyl acetate extract are identical. They are 3.12 mg / mL on S .aureus Meti R and 25 mg / mL on P. aeruginosa Cefta R & Imp.R. After column purification, the activity was improved leading to MIC and MBC values of 1.56 mg / mL on S. aureus Meti R and 12.5 mg / mL on P. aeruginosa Cefta R & Imp.R. Antimicrobial tests showed that leaves extract of vernonia colorata can develop bactericidal activities on resistive gram-positive and gram-negative germs such of S. aureus resistant to methicillin and P. aeruginosa resistive to ceftazidime and imipenem.