In the article there were discussed the transformations of views on armoured and mechanised troops used to fight against irregular forces in selected armed conflicts after World War II, i.e. Vietnam, Afghanistan and Chechnya. During the armed conflict in Vietnam the armoured and mechanised intervention and Saigon’s forces were used, among other things, to reconnoitre the probable location of Vietcong units, to carry out direct support to the infantry and airborne subunits in the anti-guerrilla operations, to reinforce defence of the bases, to defend the important transportation routes and bridges, to cover the marching troops as well as transports of different destination. In Afghanistan, the Russians, after their first failures, tried to take advantage of American experience from Vietnam, adjusting it only to the different terrain conditions. Heavy, mechanised tactical units were exchanged for the small, independently operating ones. The same strategy was applied in Chechnya. After the failures of tank attacks at Grozny, the tactics was changed. Instead using tanks in massive attacks, some small 10-100-person assault groups were created to strike at selected targets. In the conclusion, there were indicated the tendencies that appear in the tactics of using armoured and mechanised troops to fight against irregular troops.