Detailed experiments were performed with gas phase biotrickling filters treating vapors of methyl tert-butyl ether (MTBE), a gasoline additive of great environmental concern. A particular emphasis was placed on the analysis of the rate-limiting step, and it was found that the process was mostly limited by the biological reaction rather than by mass transfer. Further experiments involved the study of the dynamic behavior of the biotrickling filters under simulated field conditions. In all cases, the biotrickling filters adapted rapidly to the new conditions, and new steady states were obtained within hours. The relevance of the results and the implications as far as implementation of biotrickling filters for field MTBE treatment are discussed.