AbstractThis chapter reviews the significant contributions to the field of soil ecology made using terminal restriction fragment length polymorphism (T-RFLP), and provides an example of T-RFLP data on microbial communities in soil microsites. Details of the factors to be considered when performing T-RFLP or interpreting data are given. Also discussed are the advantages and disadvantages of polymerase chain reaction-based community profiling methods in general, and T-RFLP in particular, and modifications to T-RFLP that can be used to ameliorate some of the disadvantages.