Rickettsia species are gram-negative intracellular, small pleomorphic coccobacilli in the Rickettsiaceae family. This genus is serologically and genotypically divided into four groups as spotted fever group, typhus group, Rickettsia belli and Rickettsia canadensis. Rickettsia conorii (R.conorii subsp. conorii) in the spotted fever group was reported to cause mediterranean spotted fever in Europe, especially in mediterranean countries including Turkey. The major vectors of Rickettsia species are ticks, and in some species fleas or mites. In this report a case with R.conorii infection was presented. A 46-year-old female patient, who had anorexia, fatigue, muscle aches, chills and high fever was admitted to a health institution. The patient was diagnosed as influenza. There was no regression in the patient's complaints with the recommended treatment. The patient was examined in our infectious diseases clinic and had several symptoms like severe muscle and joint pain with significant headache, and rashes at her body including hands and feet. The patient had a single eschar in the upper midline of the belly that matched tick biting and pink small maculopapular scars on the trunk, arms, legs, feet, and hands. Considering a Rickettsia pre-diagnosis, liquid electrolyte and doxycycline 2 x 100 mg oral treatment was started. On the third day of treatment, high fever, muscle and joint pain were decreased. On the fifth day, active skin lesions were started to fade. R.conorii IgM and IgG were negative in the first serum sample of the patient. In the biopsy sample taken from eschar tissue, Rickettsia spp. was detected as positive with rt-PCR. PCR was used by using the specific regions of the genetically specific gltA and ompA genes in the biopsy specimens and then the PCR products were determined by DNA sequence analysis. The DNA sequence results were compA red with Genbank data and determined that the gltA sequence was 99%, similar to R.conorii with accession number JN182786 and the ompA sequence was 99%, similar to R.conorii with accession number KR401144. When the phylogenetic tree was created, it was observed that the etiological agent was R.conorii. A week after the treatment, in the second serum sample R.conorii IFA IgM 1/192 titer and IgG 1/320 titer were detected as positive. In this case report, we have presented a Rickettsia case, clinically diagnosed as Rickettsia, serologically negative in the acute phase, PCR positive, with post-treatment seroconversion and etiologic agent determined as R.conorii.