The calculated distance (air line) between Surčin and Sremska Mitrovica is approximately 35 miles respectively 56 kilometers.
By car or train, the actual journey to Sremska Mitrovica is certainly longer, as only the direct route (as the crow flies) between Surčin and Sremska Mitrovica has been calculated here.
Air line (approximately)
56 kilometers
30 nautical miles