broad gauge: 1,328 km 1.520-m gauge (1992)

Monaco: total: 1.7 km

standard gauge: 1.7 km 1.435-m gauge

Mongolia: 1,815 km

broad gauge: 1,815 km 1.524-m gauge (2001)

Montserrat:
0 km

Morocco:
total: 1,907 km

standard gauge: 1,907 km 1.435-m gauge (1,003 km electrified; 540
km double track)

Mozambique:
total: 3,131 km

narrow gauge: 2,988 km 1.067-m gauge; 143 km 0.762-m gauge (1994)