Chemiluminescence (CL) monitoring has successfully been applied to the study of the oxidative degradation of two-component polyethylene blends made with commercially available low-density polyethylene, linear low-density polyethylene, high-density polyethylene, and metallocene-catalyzed linear low-density polyethylene (mLLDPE) formulations. The emphasis in the analysis of the results is placed on blends containing mLLDPE to address the lack of CL information on these blends. The CL data are consistent with the thermal and physicomechanical properties of the blends, with a decreased blend miscibility being reflected in the CL data as a departure from the idealized behavior observed for more miscible blends. Furthermore, the results suggest that immiscibility in the solid state is reflected to some extent in the behavior of the melt. Preliminary experiments conducted to determine the level of consistency of CL results with respect to both variability between instruments and variability between techniques indicate a high degree of correlation in each case. (C) 2003 Wiley Periodicals, Inc.