Currently, antimicrobial resistance is one of the major threats tohealthcare as multidrug-resistant strains of bacteria, yeasts, and molds continue to emerge. To address this issue, innovative solutions are needed, and one promising approach is the development of gemmotherapy extracts (GTEs) from plant parts such as buds and young shoots. In the current study, the antimicrobial activity of eight GTEs—raspberry, blackthorn, sea buckthorn, dog rose, lingonberry, hawthorn, common grapevine, and boxwood—was analyzed using agar diffusion and broth microdilution methods. The latter technique was used to determine the minimum inhibitory concentration (MIC) and the minimum bactericidal concentration (MBC). The antimicrobial efficacy was tested against seven bacterial strains, five mold strains, and two yeast strains, which can cause different health conditions in the human body. Using the agar-diffusion method, we found that Gram-positive bacteria showed good susceptibility, as lingonberry and dog rose GTEs formed inhibition zones even at a concentration of 10-20% in the case of Bacillus cereus and Staphylococcus aureus. On the contrary, none of the GTEs showed activity against Gram-negative bacteria, molds, or yeasts. By the broth microdilution method, we observed that dog rose and lingonberry GTEs were the most effective, inhibiting the growth of Gram-positive bacteria even at relatively low concentrations (10-40%). Gram-negative bacteria were more resistant to most GTEs, as only concentrations above 40-50% showed bacteriostatic effects. Yeast strains were the most resistant, as only concentrations above 60% were effective. Although the bactericidal effects were minimal, the GTEs from the lingonberry and the common grapevine were effective against five strains of bacteria, such as Enterococcus faecalis, Listeria monocytogenes, Enterococcus faecalis, Pseudomonas aeruginosa, and Salmonella enterica, with an MBC of 60-70%. Based on the antimicrobial properties observed, especially for dog rose and lingonberry GTEs, these extracts could be considered as potential agents to enhance the efficacy of antibiotic therapies.