Abstract: Air is the greatest dissemination agent of pathogenic microbes which cause significant problems in the hospital environment.

Objectives of the Study: To determine bacterial indoor air concentrations, to identify the bacterial isolates and determine antibiotics resistance patterns present in indoor air in a hospital wards at Hawassa University comprehensive specialized Hospital.

Methodology: In this cross sectional study, 6 wards in Hawassa comprehensive specialized hospital were studied. Sample collection was carried out twice a day, mornings and afternoon with an interval of 14 days. Sedimentation technique using open petri dishes containing sheep blood agar was used. An openculture medium was placed 1 meter above the floor for 1 hour at selected sections of the wards and transported aseptically to the Microbiology laboratory. Types and number of colonies were determined in the laboratory. Then isolates were identified by appropriate bacteriological techniques. The SPSS version 16.0 software was used for data management. P- Value of < 0.05 was used as Statistical association.

Result: The finding of this study indicated that the highest indoor bacterial count was observed at medical common ward which is 7958.98 CFU/ m3 and a least count was recorded at neonatal intensive care unit of 930 CFU/ m3 withthe average count of 4420 + 1642 CFU/ m3. Out of 96 indoor air sampled 41 (43%) were below satisfactory limits. Among the 6 sampled wards, neonatal intensive care unit was the most unsatisfactory area for patients with 11/16 (69%) air sampled were undesirable. The predominant isolates were S. aureus(36%), Coagulase negative staphylococci (28.8.9%), followed by Pseudomonas spp. (13.5%). The study revealed that, similar to others findings most of isolates were resistant for the tested antibiotics.

Conclusions: Regardless of number of students and visitors, the neonatal intensive care units need to get appropriate emphasis to prevent newborns from nosocomial infection risk as their immunity debilitated. Bacteriology of the isolates remained troublesome because of the resistance pattern of the isolates to commonly prescribed antibiotics. Therefore, hospitals should have enhanced practice of good sanitation protocols and infection control measures.