| Rank | Country | narrow gauge | Railways |
| Laos | | void |
| Lesotho | | void |
| Libya | | 0 km note: Libya has announced plans to build seven lines totaling 2,757 km of 1.435-m gauge track (2006) |
| Liechtenstein | | 9 km 1.435-m gauge (electrified) note: belongs to the Austrian Railway System connecting Austria and Switzerland (2006) |
| Lithuania | | total: 1,771 km broad gauge: 1,749 km 1.524-m gauge (122 km electrified) standard gauge: 22 km 1.435-m gauge (2006) |
| Luxembourg | | total: 275 km standard gauge: 275 km 1.435-m gauge (243 km electrified) (2006) |
| Macau | | void |
| Macedonia | | total: 699 km standard gauge: 699 km 1.435-m gauge (223 km electrified) (2006) |
| Maldives | | void |
| Malta | | void |
| Marshall Islands | | void |
| Mauritania | | 717 km standard gauge: 717 km 1.435-m gauge (2006) |
| Mauritius | | void |
| Mayotte | | void |
| Mexico | | total: 17,665 km standard gauge: 17,665 km 1.435-m gauge (2006) |
| Micronesia, Federated States of | | void |
| Moldova | | total: 1,138 km broad gauge: 1,124 km 1.520-m gauge standard gauge: 14 km 1.435-m gauge (2006) |
| Monaco | | void |
| Mongolia | | total: 1,810 km broad gauge: 1,810 km 1.524-m gauge (2006) |
| Montenegro | | total: 250 km standard gauge: 250 km 1.435-m gauge (electrified 169 km) (2006) |
| Montserrat | | void |
| Morocco | | total: 1,907 km standard gauge: 1,907 km 1.435-m gauge (1,003 km electrified) (2006) |
| Nauru | | void |
| Navassa Island | | void |
| Netherlands | | total: 2,797 km standard gauge: 2,797 km 1.435-m gauge (2,064 km electrified) (2006) |
| Netherlands Antilles | | void |
| New Caledonia | | void |
| Niger | | void |