The calculated distance (air line) between Trstenik and Sremska Mitrovica is approximately 116 miles respectively 187 kilometers.
By car or train, the actual journey to Sremska Mitrovica is certainly longer, as only the direct route (as the crow flies) between Trstenik and Sremska Mitrovica has been calculated here.
Air line (approximately)
187 kilometers
101 nautical miles