Fishmeal and fish oil have been considered the most digestible and nutritious ingredients for farmed fish, but there is a shift towards more sustainable alterna tives. In this study, fish oil was replaced with microbial oil based equivalents. Atlantic salmon ( Salmo salar) were fed four different diets, two included microbial oil at low and high levels of inclusion, while one contained fish oil as well as canola oil, the fourth was a control diet containing traditional fish oil. Sterols were Identified and quantified in salmon muscle tissue after feeding trials with different levels of microb ial oil, fish oil, and canla oil using gas chromatography/mass spectrometry (GC/MS) and gas chromatography/flame ionization detection (GC-FID). Results indicate that cholesterol content decreased in the microbial diets as compared to the fish oil diet. There were phytosterols identified in the microbia l oil diets that were not present in the fish oil diet. In the salmon muscle, cholesterol content decreased in fish fed the fish oil/canola oil diet, but did not change in salmon fed the microbial oil diets.