Bacterial communities from the sulfide containing curative well waters of Harkány Spa (Hungary) were investigated by cultivation independent molecular cloning and Denaturing Gradient Gel Electrophoresis (DGGE) methods between 2006 and 2008. The DGGE profiles of the bacterial communities originated from the wells of lukewarm waters showed seasonal similarities and were highly different from the thermal well. From the four clone libraries 22 different eubacterial species or genera were identified by sequence analysis. The majority of the clones of the lukewarm waters belonged to unidentified Epsilon-proteobacteria, Desulfocapsa sp. and Thiothrix spp., while the dominant clones of the thermal water were affiliated with the genus Denitratisoma sp. Most of the identified species and genera were related to bacteria with obligate or facultative chemolithotrophic sulfur metabolism, so the microbes of the curative waters may participate in the sulfur-cycle of the wells.