Propolis has highly biologically active natural substances. Propolis is rich in phenolic compounds, and is becoming increasingly popular because of its components' potential role in contributing to human health. Its composition is variable and depends on several factors. In this study, some individual phenolic compounds were analyzed and investigated in vitro biological activities of ten different Turkish propolis samples. Seventeen different phenolic constituents were measured by reverse phase-high performance liquid chromatography. Total phenolic compounds and ferric reducing antioxidant power were used as antioxidant capacity determinants. The antimicrobial activity was studied by agar diffusion method using six bacteria and two yeasts. All propolis showed strong antioxidant and antimicrobial activity and contained large amounts of antioxidant compounds. Quercetin, benzoic acid, caffeic acid, ferulic acid, and coumaric acid were detected in all propolis samples in high amounts, while vanillic acid, chlorogenic acid, epicathecin, rutin, syringic acid, and o-coumaric acid were found in very small quantities and cathecin was not found in any of them. The methanolic extracts were active against all bacteria and yeasts. They were especially effective against Pseudomonas aeruginosa ATCC (R) 27853. The propolis extracts proved to be a good source of antioxidants and antimicrobial agents that might serve to protect health and fight against several diseases.