In this paper, described are the results of full-scale measurements and stress analyses on the transverse strength of car carriers, with special reference to the local strength of partial bulkhead constructions above free-board deck of the ships. The unmanned stress measurements have been carried out on three voyages of ship A and six voyages of ship B, respectively, and the maximum stress amplitude obtained at face plate of a round corner of the partial bulkhead has been 13 kg/mm². A close correlation has been found from the measured data between the stresses in the transverse members and the accerelation in athwartship direction due to ship's motion. Stress analyses based on the finite element method have been carried out on structural models of the car carriers, and the results have shown that a relatively high stress occurs in the partial bulkhead structures due to racking deformations of the transverse cross section of the ship caused by anti-symmetric load with respect to ship centre line. A comparison has shown a good coincidence between the measured value of the maximum stress in the transverse members and the theoretically estimated statistical value by the present analysis.