The Central Andean Highlands are the center of origin of the potato plant (Solanum tuberosum). Ages of mutualism between potato plants and soil bacteria in this region support the hypothesis that Andean soils harbor interesting plant growth-promoting (PGP) bacteria. Therefore, the aim of this study was to isolate rhizobacteria from Andean ecosystems, and to identify those with PGP properties. A total of 585 bacterial isolates were obtained from eight potato ﬁelds in the Andes and they were screened for suppression of Phytophthora infestans and Rhizoctonia solani. Antagonistic mechanisms were determined and antag- onistic isolates were further tested for phosphate solubilization, 1-aminocyclopropane-1-carboxylate (ACC) deaminase activity, and production of NH3 - and indole-3-acetic acid (IAA). PGP was studied in healthy and R. solani diseased plantlets under growth room conditions. Performance was compared to the commercial strain B. subtilis FZB24® WG. Isolates were dereplicated with matrix-assisted laser desorption/ionization time of ﬂight mass spectrometry (MALDI-TOF MS), and identiﬁed with 16S rRNA gene sequencing and multi locus sequence analysis (MLSA). A total of 10% of the isolates were effective antagonists, of which many were able to solubilize phosphate, and produce IAA, ACC deaminase, NH3 and hydrogen cyanide (HCN). During growth room experiments, 23 antagonistic isolates were associ- ated with plant growth-promotion and/or disease suppression. Ten isolates had a statistically signiﬁcant impact on test parameters compared to the uninoculated control. Three isolates signiﬁcantly promoted plant growth in healthy plantlets compared to the commercial strain, and seven isolates outperformed the commercial strain in in vitro R. solani diseased plantlets.