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Phenazine-1-carboxylic acid (PCA) produced by plant-beneficial <i>Pseudomonas</i> spp. is an antibiotic with antagonistic activities against <i>Phytophthora infestans</i>, the causal agent of potato late blight. In this study, a collection of 23 different PCA-producing <i>Pseudomonas</i> spp. was confronted with <i>P. infestans</i> in potato tuber bioassays to further understand the interaction existing between biocontrol activity and PCA production. Overall, the 23 strains exhibited different levels of biocontrol activity. In general, <i>P. orientalis</i> and <i>P. yamanorum</i> strains showed strong disease reduction, while <i>P. synxantha</i> strains could not effectively inhibit the pathogen’s growth. No correlation was found between the quantities of PCA produced and biocontrol activity, suggesting that PCA cannot alone explain <i>P. infestans</i>’ growth inhibition by phenazine-producing pseudomonads. Other genetic determinants potentially involved in the biocontrol of <i>P. infestans</i> were identified through genome mining in strains displaying strong biocontrol activity, including siderophores, cyclic lipopeptides and non-ribosomal peptide synthase and polyketide synthase hybrid clusters. This study represents a step forward towards better understanding the biocontrol mechanisms of phenazine-producing <i>Pseudomonas</i> spp. against potato late blight.