Large-scale variations in the level of the Chukchi Sea are studied based on observation data from seven stations over 22 years. A spectral analysis of the initial time series showed significant peaks with periods of 1 year and 61 - 69; 17 - 20; 8; 6; 3.7; 2.8 - 3.1; 2.3 - 2.5, and 2.06 - 2.12 days. The components of long-period tides within a range of 19 years to 10 days are calculated. Nontidal oscillations are obtained by subtracting long-period tides and an annual harmonic from the initial series. The contribution of different time-scale processes to the total variance of large-scale sea level oscillations is estimated. The character of spatial phase alteration indicates that synoptic-scale level oscillations generally represent progressive waves. Fourier analysis identified these waves as shelf waves.