Seasonal changes of biochemical composition of caramote shrimp head (CSH) and common cuttlefish viscera (CCV) were investigated. The effect of chilled storage (5C) of these by-products during 21 days on the physicochemical quality indicators was evaluated for every season to assess a suitable storage period. All biochemical components varied significantly (P<0.05) overall season for both types of by-products except moisture and chitin contents, which remained constant in CSH (79.770.33% and 8.331.11% respectively). CCV and CSH by-products were a main source of proteins (28.375.44% and 20.375.77% respectively on dry weight basis (d.w.b)) and ash (23.604.18% and 28.282.32% respectively d.w.b). Principal component analyses (PCA) proved that CSH could be upgraded to obtain a rich product in minerals and chitin components at any time regardless the season. CCV collected in spring and summer could be assimilated as a homogenous group rich in protein and lipid. The chilled storage CCV and CSH during 21 days showed significant (P<0.05) variations of some physicochemical indicators and according to PCA, by-products might be stored just for few days (not more than a week) as proteolysis and lipolysis increased from the first week.