Monkeypox (mpox) caused by the monkeypox virus (MPXV) is currently the most common orthopoxvirus (OPXV) zoonotic disease. Since 2022, a multi-country outbreak of mpox has been reported with atypically rapid human-to-human transmission. The present work aimed to investigate the frequency of MPXV and OPXV DNA detection in different clinical materials taken at acute and convalescent phases of the infection in Bulgarian patients. A total of 181 clinical samples from 42 Bulgarian patients with possible mpox infections were tested. Screening for MPXV DNA (F3L gene) and OPXV DNA (rpo18 gene) were performed by real-time PCR assays. Of all tested patients six (14%) were confirmed with mpox infection. MPXV DNA was detected in 23/181 (12,71%) and OPXV DNA in 20/181 (11,05%) clinical samples. All confirmed patients were men who have sex with men, aged 23 to 44 (at an average age of 35,17±7,91 years) and two of them were HIV positive. The commonest clinical features of patients were fever (5/6), vesicular-pustular rash: perianal (6/6), penile (4/6), and limbs (4/6). MPXV DNA was found with the greatest frequency in specimens of vesicle contents and nasal/oropharyngeal swabs in 6/6 and 5/6. OPXV DNA mainly was detected in vesicle contents (6/6), nasal/oropharyngeal swabs (4/6), and urine (4/6). In the collected follow-up samples, MPXV DNA was detected in the highest percentage in the specimen's vesicle contents (6/6) and urine (6/6) and not demonstrated in samples of feces and saliva. The laboratory surveillance of MPXV is critical to contain the outbreak and to elucidate the new fast transmission of the virus.