In the present paper, a computational model for cell contraction of an elastic substrate is proposed. Axisymmetry is assumed and the cell is represented by its contractile apparatus, which is taken to consist of radially oriented stress fibres. The constitutive behaviour of the contractile apparatus is modelled by use of a strain energy function, and contraction of stress fibres is modelled by giving them a different natural configuration compared with the underlying elastic substrate. The model was compared with experiments, in which fibroblasts were put on an elastic substrate. The contracted cell radius depends on the stiffness of the elastic substrate, and model predictions were compared with the experimental results for different values of the stiffness of the elastic substrate. The model also predicts that the contraction of the cell tends to cause a small crater below the cell, which is qualitatively in agreement with experimental observations.