Dietary phospholipid requirements in Atlantic salmon were last investigated a quarter of a century ago in relatively short-term studies (12–16 weeks), using lecithin preparations with rather undefined phospholipid content and class composition. There-fore, the particular aims of the present study were to confirm the re-quirement for dietary phospholipid in Atlantic salmon, better define the level of requirement, and further establish the period of require-ment. To this end, Atlantic salmon fry were fed diets containing either krill oil or soybean lecithin in a regression design at five levels from first feeding through to parr–smolt transformation. Analyses focused on growth, mortality, vertebral malformation and intestinal histology (steatosis).