ABSTRACT
A retrospective study is composed of 23 patients with pulmonary infiltrations whose hospital records were available who underwent open lung biopsy at Siriraj Hospital from January, 1982, to December, 1986. The patients were separated into two broad groups. The first, there were those patients who were in clinically stable condition. The second group identified patients who were systemically ill and whose course was rapidly deteriorating. Time delayed in diagnosis was critical in these patients whose urgent and correct treatment was necessary. Open lung biopsy revealed correct diagnosis in all patients. The prospective diagnosis was changed in 60.87 percent of all patients and the biopsy results altered therapy in 56.52 percent. Hence open lung biopsy appears to be a valuable procedure with low morbidity and mortality in patients who have otherwise undiagnosable pulmonary infiltrations.