Three hundred and seventy one sera sampled in different period since the onset of the disease from 214 patients with Ixodes tick-borne borreliosdes (ITBB) caused by Borrelia afzelii and B. garinii in the Perm Region (Russia) and 299 sera from 222 patients with other diseases were simultaneously tested for IgM and IgG antibodies by using immunofluorescence assay (IFA) with standard antigen from strain Ip-21 B. afzelli by indirect micromodification of enzyme immunoassay (IMELISA) on slides and routine enzyme immunoassay (ELISA) with standard commercial test systems (Medipan Diagnostica GmbH, Germany). It is concluded that IMELISA is a technically easy and accessible test, which is close to IFA in its specificity and sensitivity, and can be widely used for serological verification of ITBB.