Sputum Gram stain was diagnostic for pulmonary strongyloidiasis in four patients from Tennessee with chronic obstructive lung disease treated with steroids. The case reports of these patients and photomicrographs of the larval forms by Gram stain are presented. Sputum Gram stain may be a useful procedure to screen for pulmonary strongyloidiasis in steroid-treated patients with chronic lung disease who come from an endemic area.