In a lung ultrasound examination, interstitial lung lesions are visible as numerous B-line artifacts, and are best recorded with the use of a convex probe. Interstitial lung lesions may result from many conditions, including cardiogenic pulmonary oedema, non-cardiogenic pulmonary oedema, or interstitial lung disease. Hence difficulties in the differential diagnostics of the above clinical conditions. This article presents cases of patients suffering from interstitial lung lesions discovered in the course of lung ultrasound examination. The patients were examined with a 3.5–5.0 MHz convex probe and a 7.0–11.0 MHz linear probe. Ultrasound images have been analysed, and differences in the imaging with both probes in patients with interstitial lung lesions have been detailed. The use of a linear probe in patients with interstitial lung lesions (discovered with a convex or a micro-convex probe) provides additional information on the source of the origin of the lesions.