The calculated distance (air line) between Lazarevac and Sremska Mitrovica is approximately 52 miles respectively 83 kilometers.
By car or train, the actual journey to Sremska Mitrovica is certainly longer, as only the direct route (as the crow flies) between Lazarevac and Sremska Mitrovica has been calculated here.
Air line (approximately)
83 kilometers
45 nautical miles