One hundred and fifty three enterobacteria isolated from eight different hospitals in Bogota, Colombia, from 2002 to 2005, were studied in order to determine class 1 integrons presence and their relationship with isolates’ resistance phenotype. MATERIAL AND METHODS. Genes intI1, 1, and sul1 were detected by polymerase chain reaction. Variable region of integrons was analyzed by RFLP-PCR. Association between integrons presence and resistance to different classes of antibiotics was done using Fisher test. RESULTS. Seventy nine point nine percent of isolates studied showed class 1 integrons. Restriction Fragment Length Polymorphism (RFLP-PCR) of integrons variable regions revealed 16 different gene arrays. Genes most commonly found were those codifying for streptomycin (79.4%), trimethoprim (34.3%) and -lactams (18.6%) resistance. Additionally, one new cassette array identified on the variable region of was reported for the first time in this study. We found significant statistical association between streptomycin and trimethoprim resistance with presence of class 1 integrons. CONCLUSIONS. Class 1 integrons are widespread in enterobacteria isolates studied, and their presence is associated with streptomycin and trimethoprim resistance whereas other antibiotic resistance was not associated with these structures.