The calculated distance (air line) between Leskovac and Sremska Mitrovica is approximately 179 miles respectively 289 kilometers.
By car or train, the actual journey to Sremska Mitrovica is certainly longer, as only the direct route (as the crow flies) between Leskovac and Sremska Mitrovica has been calculated here.
Air line (approximately)
289 kilometers
156 nautical miles