A summary of the different applications of the group-contribution lattice-fluid theory is presented. The group contribution lattice-equation of state (GCLF-EOS) takes it roots in the model developed by Panayiotou and Vera (1981). Its statistical thermodynamic background makes it as amenable to small molecules as well as macromolecules. In this model, each molecule is characterized by two scaling parameters: a hard core-volume and a term that accounts for the molecular interactions. High and Danner (1989) have developed a group contribution method for the calculations of these scaling parameters. More recently Lee and Danner (1996) have revised this method and added a group-contribution correlation to evaluate the interaction parameter for mixtures. Muralidharan (1998) proposed a second mixing rule for the interaction parameter. After a brief recapitulation of the GCLF-EOS the different areas where GCLF-EOS was applied are presented and illustrated with some examples.