The distribution of the trace gases N2O, CFCl3, and CF2Cl2 is influenced by the O2 absorption cross sections. There has been a recent indication in the literature that the O2 cross sections used in past model studies may overestimate the true values. We have used a two-dimensional model to perform a sensitivity study on the effects of changes in the O2 cross sections on N2O, CFCl3, and CF2Cl2. Decreases in the O2 cross sections between 180 and 230 nm resulted in altitude-, latitude-, and season-dependent reductions in the computed species' concentrations. The altitude dependence of the reductions at mid-latitudes agrees qualitatively with similar one-dimensional model studies (Froidevaux and Yung, 1982; Brasseur et al., 1983). The vertical profiles of CFCl3 are most affected and the vertical profiles of N2O are least affected by the O2 cross-section changes. The greatest changes in the trace gases occur above 20 km, at high latitudes, and in the winter. In general, the reduced O2 cross sections led to better agreement between model calculations and experimental measurements for all three trace gases; however, there still remain some unexplained differences between observations and model predictions. This result implies that the reduced O2 cross sections may be the better set. The accuracy of the lifetime calculations for the trace gases is not sufficient to recommend either set of O2 cross sections. More precise measurements of O2 absorption cross sections are thus required to determine the true values.