Energy efficiency and annual emissions from freight and passenger transportation with diesel locomotives in Turkey have been calculated. The main criterion in efficiency was taken as gross.ton.km, and the fuel spent for 1 grosston.km cruising and the grosston.km traveled with 1 liter of fuel were calculated for the 5-year period covering the years 2013-2017. Compared to the end of the period, it was observed that the amount of fuel consumed for 1 grosston.km cruising decreased and the value of grosston.km traveled with 1 liter of fuel increased. It was observed that the total emissions of HC, CO, NOx and PM10 pollutants peaked in 2014 and decreased in the following years. CO and NOx emissions were the highest. The highest amount of pollutants belongs to CO and NOx emissions. As solutions; increasing the use of electric loco, especially for ore transport and heavy hauls. Suggestions were made to give priority to the construction of double lines in regions with heavy cargo transportation, with the widespread use of the CTC system to reduce energy costs and emissions, and to carry out the transportation in the operating regions where heavy tonnage transportation is carried out.