This article is report of the study on the gastric aspirate findings in infants with pneumonia and in healthy controls. The materials were consisted of 20 cases of pneumonia and 20 cases of healthy controls under the age of 1 year who were admitted to the pediatric department and children's hospital of Presbyterian Medical Center, Daegu, Korea during the period of Jan. 1976 through Aug. 1976. The following results were obtained: 1) The gastric aspirate finding of pneumonia group was associated with thicky mucoid gastric fluid containing a high proportion(80.4%) of polymorphonuclear leukocytes in contrast to a low proportion (19.6%) of epithelial cells. 2) Healthy controls had thin fluid and predominance (85.2%) of epithelial cells in contrast to a low porportion (14.8%) of polumorphonuclear leukocytes in the gastric smear. 3) The bacteriological culture from gastric aspirate revealed positive results of 35% in pnuemonia group and 15% of healthy controls. 4) It is suggested that gastric aspirate cellularity is of diagnostic value for pneumonia of infancy rather than the bacteriological culture and over 60% of polymorph. Count on the smear of the materials indicated underlying infection.