This paper presents a study of the shear lag effects on the behaviour and strength of welded steel single angle tension members. A total of thirteen single angles with welded end connections were tested in tension. The test parameters included long and short leg connections, balanced and unbalanced weld arrangements and longitudinal fillet weld lengths. Out of the thirteen specimens, nine failed by fracture of the gross section and four failed in the welds. The efficiency of the specimens, which is defined as the ratio of the test ultimate load (P) to the tensile capacity (a product of the gross sectional area and the tensile strength of the material) of the specimens varied from 0.82 to 1.02. It can be observed from the test results that both the ultimate loads sustained by the short leg connected angles and the ductility of all the angle specimens were greater when the balanced weld arrangement was used in the connections than when the specimens were connected using the unbalanced welded arrangement. Finite element analyses of the specimens were conducted and the analysis results compared well with the test results. The capacities of the test specimens were also evaluated using various design approaches. In general the design specifications (AISC-LRFD, BS5950-1:2000, and CSA-S16-01) provided good predictions of the tensile capacity of the single angle specimens with a reasonable degree of conservatism. However, the design specifications underestimated the tensile capacity of specimens which were connected by the short leg and with a balanced weld arrangement.