In this work, we observed and investigated electro-luminescence (EL) from defects in 4H-SiC avalanche photodiodes. The EL irradiance originated from parallel lines oriented along the [11-20] crystallographic direction. Optical microscopy imaging was employed to analyze the intensity distribution of luminescencing lines at different current densities. Electron beam induced current (EBIC) methodology was employed to find correlation between the luminescencing defects and dislocations in the epi-layers. TEM analysis of the substrate region having the brightest luminescencing line was performed. There were a few defects at the depth of about 3 μm from the sample surface where EL intensity had the highest value.