The bioactive constituents of five Nigerian plants in use in Traditional medicine namely, Spindias mombin (family: Anacardinaceae), Calliandra portoricensis (family: Fabaceae), Dennettia tripetala (family: Annonaceae), Anthocleista djalonensis (family: Loganiaceae) and Croton zambasicus (family: Euphoirbiaceae), were investigated for antimicrobial activities. The morphological parts of the plants evaluated were the leaf and root. The dried and pulverized samples were subjected to successive extraction using organic solvents; n-hexane, ethylacetate and 70% aqueous methanol. The respective extracts were concentrated en vacuo using a rotatory evaporator at less than 40o C. Seven human pathologically viable and clinical strains of microganisms comprising the G+ve, G-ve, fungi and nocosomial strains were used as test organisms, ciprofloxacin and fluconazole solutions served as the control reference standards. Agar well diffusion assay method was used and the Inhibition Zones of growth were measured to assess activities for all the extracts. The Minimum Inhibitory Concenyrations (MIC) and Total Activity (TA) were also determined. C. zambasicus exhibited a broad antibacterial activity whereas C. portoricensis showed the best spectrum of both antibacterial and antifungal activities. The extract of D. tripetala ranked lowest in activity of all the test samples. Ethyl acetate extracts ranked the highest of all the three organic solvents used for the study.