Halogenating enzymes increasingly attract attention for biocatalytic C-H functionalization. Despite the importance for synthetic chemistry, selective introduction of halogens using conventional approaches often remains challenging, whereas biocatalysis offers excellent catalyst-controlled selectivity without requiring protecting groups or hazardous reagents. Owing to the high prevalence of halogenated secondary metabolites, a still growing repertoire of halogenases has been identified. Recently, flavin-dependent tryptophan halogenases turned into focus for synthetic use. Nevertheless, these enzymes still suffer from severe deficiencies. Our research is focused on the identification of novel halogenases, random and rational engineering, high-throughput screening and implementation of halogenases into one-pot processes for synthetic approaches.