To predict the structural behaviour of the Humber Bridge under different loading conditions, geometrically non-linear finite element (F.E.) models were used- Analyses were validated against available field measurements. Main cable forces and hanger forces from the F.E. models―were calculated under the dead load condition and compared with the designer's frame analysis results. Vertical displacements at the bridge mid-span and quarter-span were calculated when a heavy load moved slowly from one end to the other, and results compared with data from in-situ tests. Natural frequencies and associated mode shapes of the bridge were also calculated and comparisons were again made with field measurements. An acceptable model of the in-service behaviour of the bridge has resulted. Consequently, the behaviour of the bridge has been analysed under revised traffic load, wind load and change in temperature.