Whether direct availability of organic compound solubilized in nonionic surfactant micelles (bioavailability) in a bioremediation or biotransformation process is uncertain to some extent, which is partially attributed to the difficulty by direct experimental determination. In another point of view, it should be ascribed to the fuzzy concept about the solubilization of organic compound in a nonionic surfactant micelle aqueous solution. In this mini-review, the solubilization of organic compound in surfactant micelles aqueous solution is fully discussed; especially saturated solubilization and unsaturated solubilization have been emphasized. Then the current methods for estimation of bioavailability of organic compounds solubilized in micelles are introduced, in which the possible drawbacks of each method are stressed. Finally, the conclusion that organic compound solubilized in micelles is unavailable directly by microbes has been drawn and the intensification of bioremediation or biotransformation by nonionic surfactant micelle aqueous solution is contributed to enhancement of the hydrophobic organic compounds dissolution.