Abstract: Four strains of selected TBT-resistant bacteria were tested for growth in the presence of methylmercury. Results indicate their potential of detoxification not only of TBT but also were resistant to MeHg. The EC50 of these four is bacterial isolates; Pseudomonas fluorescens, Enterobacter cloacae, Citrobacter braakii and Alcaligenes faecalis were 0.32, 0.39, 0.34 and 0.35 μM MeHg, respectively. Enterobacter cloacae has been shown in this study to exhibit high resistance to the toxic effects of MeHg as it is previous reported to show similar high resistance capability to TBT. These bacteria species were also examined for their biodegradability and it has found that they shows capability of degrading MeHg even in the absence of primary nutrient-glycerol, suggesting that these microorganism can utilise the carbon-source in the pollutant in order to mineralise the organic compound. This study has successively proven for the first time that these four selected TBT-resistant bacteria species were both efficient MeHg resistant and degrader. Enterobacter cloacae is the most preferable as highly effective resistant TBT and MeHg degrader and thus recommended for future use.