Graph theory plays an important role in the chemical sciences to model chemical compounds graphically. A chemical graph is a representation of molecular structure whose vertices are considered as atoms of the molecule and edges are the bonds between them. A topological index is a numeric quantity associated with chemical compounds to predict various physicochemical properties and biological activities theoretically. The sum of the cube of degrees of all the vertices for a graph is called the ``forgotten topological index'' or F-index of that graph. In this study, we compute the F-index of double corona graphs related to the different subdivision graphs.