From 2001 to 2004, we carry on a survey on the utilization of ampicillin among some diarrheagenic patients attending some Teaching Hospitals in Nigeria. From the result 723(58.2%) volunteers responded to the questionnaires, where only 83(11.4%) consult a doctor for prescription, 397(54.9%) from drug retailers while 142(20.1%) self prescribe and 56(7.7%) prescription was base on the advice of friends and relatives. The results also indicate that 229 (31.7%) take full regimen if prescribed by a doctor and 494(68.3%) stop the consumption of the drug when the signs and symptoms subside. Of the 249 diarrheagenic clinical isolates of E coli strains obtained from 2001 to 2004, 78 (31.3%) were obtained from UBTH, 41(16.5%) from ABUTH, 38(15.3%) from NAUTH and 92(36.9%) from UCH with a mean average of 63(25.3%). Among the antibiotics tested, ampicillin was the least susceptible antibiotics while the quinolones were the most susceptible. Most of the E coli strains screened had one or more resistant R plasmids. 52% of the E coli harbour ampicillin resistant plasmids of different molecular weights that ranged from ?0.451kbp to ?1.254kbp. Mostly Chromosomal DNA mediated most of the E coli isolates resistant to tetracycline, erythromycin, and ciprofloxacin. None of the Teaching Hospital had a surveillance method for evaluating the emergence of resistance pathogens.