Escherichia coli is a commensal bacterium of the gut microflora of the chicken. Escherichia coli infections are responsible for significant economic losses in the poultry industry world-wide. The pathogenesis and the role of virulence factors are not yet fully elucidated, although considerable progress has been made in recent years to establish the mechanisms of pathogenesis. Escherichia coli strains cause a number of diseases in domestic poultry, ultimately leading to disease and death, or to a decrease in egg and meat production or condemning of carcasses. On the other hand, our knowledge about the composition of the gut flora and microbial ecology of the gastrointestinal tract is still limited. Previous investigations have mainly used culture-dependent approaches. Studies on the composition of the intestinal flora of chickens date back to 1901 (Rahner, 1901) and were continued in the 1940s (Shapiro and Sarles, 1949), but comprehensive surveys that attempted to culture as many of the intestinal bacteria as possible were not carried out until the 1970s (Barnes et al. 1972; Salanitro et al. 1974). Such studies are technically difficult since strict anaerobic conditions have to be maintained during isolation and biochemical differentiation of the bacteria. It is well recognized that many bacteria have not been cultured yet in the laboratory because their growth requirements are still unknown. Recent molecular studies have yielded more detailed insight into the composition of the microbial community of this ecosystem (Zhu et al. 2002). The objective of this study was to develop a PCR based method for rapid quantification of Escherichia coli and investigation on its relative frequency in duodenum, jejunum, ileum and cecum of broilers.