Lightweight cemented clays have wide applications in infrastructure rehabilitation and in construction of new facilities. The strength and compression characteristics of lightweight cemented clays with non- to high swelling potential are investigated and presented in this article. The workable state, the optimum water content to produce the lightweight cemented clay, is about 1.9 times the liquid limit. The void/cement ratio, V/C, which is defined as the ratio of the void volume of clay to the cement volume, is proved to be the prime parameter governing the strength and compression characteristics of lightweight cemented clays. The fabric (arrangement of clay particles, clusters and pore spaces) reflected from both air foam content and water content is taken into consideration by the void volume while the inter-particle forces (levels of cementation bond) are governed by the input of cement (cement volume). A strength equation in terms of V/C at a particular curing time is introduced using Abram's law as a basis. From the critical analysis of test results, a mix design method to attain the target strength and unit weight is suggested. This method is useful for both engineering and economic viewpoints. (C) 2012 Elsevier B.V. All rights reserved.