The increasing mortality due to antibacterial resistance necessitates the search for novel antimicrobial agents. Hence, series of 1-R-2-([1,2,4]triazolo[1,5-c]quinazoline-2-ylthio)etanon(ol)s were synthesized, evaluated by spectral data and studied against St. aureus, M. luteum, E. faecalis, E. aerogenes, P. aeruginosa, C. sakazakii, E. coli, K. pneumonia, hospital Streptococcus spp., C. albicans and A. niger in 100, 500 µg/mL and 100 µg/disk. Substances exhibited moderate toxicity in 0.025, 0.1 and 0.25 mg/mL in bioluminescence inhibition tests of Photobacterium leiognathi. SAR exposed that introduction of 2,4-(Cl)2C6H3-, 2,5-(OMe)2C6H3-, 4-Me-2-iPr-C6H3O- and 3-iPr-C6H4O- fragments and reduction of the pyrimidine ring of R-([1,2,4]triazolo[1,5-c]quinazolin-2-ylthio)alcohols were the best modifications to promote antimicrobial activity. Molecular docking showed their good affinity into the active sites of EcPanK-AMPPNP and hDHFR. Hence, reported results will be used for subsequent QSAR model creation and purposeful antimicrobial modification of the strongest compounds.