This study was conducted with the aim of investigating the ability of Coagulase Negative Staphylococci (CoNS) for the detection of biofilms, which are considered as the main virulence factor in their pathogenicity. Three methods were used for this purpose, the tube method, congo red agar and tissue culture plate method. Thirty-seven isolates of the following bacteria were tested, which includes Staphylococcus epidermidis, S. saprophyticus, S. haemolyticus, S. hominis, S. lentus
and S. sciuri
.The results of the tube method showed that most isolates (64.5%) gave a moderate positive result, (32.3%) was weak positive and six isolates showed no ability to form biofilm, the congo red method showed that, the majority of isolates were a moderate positive result (89.3%) and nine isolates were negative for biofilm formation. As for the tissue culture plate method, the results ranged between (62.9%) a moderate positive and (31.4%) a weak positive, while only two isolates could not form biofilm. When comparing the efficiency of the three methods in detecting the ability of CoNS isolates to form biofilm, it was found that tissue culture plate method was the most efficient (94.6%), followed by the tube method (83.8%), and the congo red (75.7%).