In order to evaluate the dissemination problem of antimicrobial resistance genes in Lebanese rivers, a study of the presence and relative abundance of resistant bacteria was conducted during two different seasons. In total, more than 22500 resistant bacterial colonies were isolated with cultural techniques on selective media supplemented with antibiotics. The resistant bacteria isolated were Enterobacteriaceae, non-fermenters and Staphylococcus spp. At estuarian sites, 20.58% and 91.76% of the Gram-negative bacteria were producers of extended spectrum beta-lactamases of which 14.28% and 100% showed resistance to imipenem.