The in vitro antimicrobial activity of the active ingredient in antimicrobial magistral drug formulations and plant extracts used in folk medicine were investigated comparatively. Borax, sulfur colloid, hydrogen peroxide, benzoic acid, rivanol, brilliant green and plant extracts as active ingredients, namely: Helianthus tuberosus tuber-H2O (aqueous extract), Cydonia oblonga leaves-H2O, Allium porrum whole plant-H2O, Cistus laurifolius leaves-EtOH, Solanum muricalum-H2O, and Fumaria cilicica leaves-EtOH were studied to determine their antimicrobial activity against different bacteria and fungi (S. pyogenes, S. aureus, S. epidermidis, E. faecalis, K. pneumonia, H. influenza, P. aeruginosa, A. baumannii, E. coli, Candida albicans, C. tropicalis, C. parapsilosis, C. krusei) by using the microdilution method. The active ingredients and plant extracts showed different activities as MIC between 1->128 μg/mL. Brilliant green and rivanol as active ingredients had MIC values of 1 μg/mL against all tested microorganisms. C. oblonga leaves-H2O as well as C. laurifolius leaves-EtOH as plant extracts were indicated as having the highest antimicrobial effect in MIC value of 16 μg/ml against A. baumannii and S. pyogenes, respectively. On the other hand, F. cilicica leaves-EtOH and C. laurifolius leaves-EtOH showed the highest antifungal activity (MIC; 16 μg/mL).