Mali
total: 729 km
narrow gauge: 729 km 1.000-m gauge (2005)
Mauritania
717 km
standard gauge: 717 km 1.435-m gauge (2005)
Mexico
total: 17,562 km
standard gauge: 17,562 km 1.435-m gauge (2005)
Moldova
total: 1,138 km
broad gauge: 1,124 km 1.520-m gauge
standard gauge: 14 km 1.435-m gauge (2005)
Mongolia
total: 1,810 km
broad gauge: 1,810 km 1.524-m gauge (2005)
Montenegro
total: 250 km
standard gauge: 250 km 1.435-m gauge (electrified 169 km) (2005)
Morocco
total: 1,907 km
standard gauge: 1,907 km 1.435-m gauge (1,003 km electrified) (2005)
Mozambique
total: 3,123 km
narrow gauge: 2,983 km 1.067-m gauge; 140 km 0.762-m gauge (2005)
Namibia
total: 2,382 km
narrow gauge: 2,382 km 1.067-m gauge (2005)
Nepal
total: 59 km
narrow gauge: 59 km 0.762-m gauge (2005)