Background & Objectives: Pneumonia is one of the most fatal infectious syndromes with various etiologies. Mycoplasmas require special therapeutic approach as they are not sensitive to betalactams such as penicillin.

  Regarding lack of comprehensive studies relating to mycoplasmas' part in pneumonia in Iran, the current study was conducted.

  Methods: This is a descriptive study performed on 80 patients diagnosed with community acquired pneumonia and hospitalized in infectious diseases ward of Immam Khomeini Hospital (Ardebil, Iran) in over a one year time span.

  Blood samples for titration of anti-mycoplasmal IgGs and IgMs were taken from all patients.

  Results: Out of 80 hospitalized patients 40 were men and 40 were women. Mean age of the studied group was 59.91 years and 76.6% of patients lived in urban areas. We observed positive IgM in 5 patients (6.3%) and positive IgM in 20 patients (25%). Etiologic cause of 6 % of hospitalized patiants with community acquired pneumonia was mycoplasmal. We could not specify any particular clinical finding assisting to differentiate mycoplasmal pneumonias from other types of pneumonia. All the patients with positive IgM titrations had positive agglutination titers of 1/16 or 1/32, therefor under any circustances that performing of IgM titration is not possible, agglutination test can be used as an alternative.

  Conclusion: Approximately 6.7 % of community acquired pneumonias in adults' infectious diseases ward of Imam Khomeini Hospital, were etiologically related to mycoplasmas. Therefore, regarding limitations for PCR analysis and antibody titration, administration of antibiotics with antimycoplasmal properties is necessary.