A total of 100 samples (25 of each) of Mackerel fish (Scomber scombrus), Horse mackerel (Treacherous tracharus), Silver hake (Merluccinus bilinearis) and Shrimp (Penus kerathurus) were purchased from fishermen in Alexandria and stored at 0°C (held on ice), 4°C (refrigerator) and –10°C (home freezer), for as long as acceptable to study how time and temperature affect the quality and acceptability of fish and shellfish. Changes in the quality of fish were determined by chemical analyses which were correlated with sensory evaluation made by an experienced panel. Results from this study were compared to chemical analytical and sensory results from a corresponding study to follow changes in the quality of fish and shellfish during cold storage after harvest. Our results indicated that the iced mackerel fish (held on ice) retained its good quality characteristics for about one day post harvest. After four days, Mackerel fish quality decreased and reached the limit of unacceptability at sixth day of storage. Sensory score results of refrigerated and frozen fish showed that, it was considered organoleptically putrid (compeletly spoiled), after three days of storage at 4°C and after 12 months of storage at –10°C. Concerning Horse mackerel fish, it was of excellent quality at the fifth day of storage at 0°C, at first day of storage at 4°C and after one month of frozen storage, and it became spoiled, at the 15^th day, 6^th day and 13^th month of storage at 0,4 and -10°C, respectively. However, in case of Silver hake, sensory score results showed that at the second day of storage at 0 and 4°C, it began to loss its quality (border line) and became compeletely spoiled at sixth and fifth days of storage at 0 and 4°C, respectively, and at the 14^th month of frozen storage (-10°C). Regarding, Shrimp quality, it was of excellent quality for one day of storage at 0°C and became compeletly spoiled at 6^th day of storage, at the mean time, shrimp stored at 4 and -10°C showed compelete signs of spoilage after one day and one month., respectively. Results of chemical analyses of the examined fish and shellfish indicated that the mean highest total volatile nitrogen (TVN) (118.30 mg/100gm) was found in shrimp stored at –10 °C for one month while the lowest (18.78mg/100gm) was in fresh Silver hake fish. Concerning lipid spoilage parameters, Silver hake fish stored for 14 months at –10 °C showed the highest mean values of free fatty acids (FFA) (4.63 ml/gm), acid value (AV) (9.260ml/gm), fresh mackerel fish had the highest level of conjugated dienes (CD) (0.122n.mole/mg), while Shrimp stored at –10 °C for one month had the highest mean values of thiobarbeturic acid value TBA (6.542mgMA/kg). At the same time, fresh Horse mackerel fish showed the lowest mean values of FFA (0.554 mg/ml), TBA (0.339 mgMA/kg and AV (1.108ml/gm), while Mackerel stored at –10 °C for 12 month showed the lowest value of CD (0.009n mole/mg). Results of shelf life of the examined fish during cold storage indicated that iced Mackerel was inedible after 6 days, refrigerated one was putrid after 3 days and frozen mackerel had spoiled after 12 months. Regarding horse mackerel fish, shelf life was 15,6 days for iced and refrigerated storage and 13 months for frozen storage. However, Silver hake had shelf life of 6,5 days for iced, refrigerated storage and 14 months of frozen storage. In case of Shrimp, complete spoilage began after 6,1 days, I month of storage at 0,4 and –10 °C, respectively. Statistical analytical results indicated the presence of strong correlation between sensory scores and chemical parameters in all the examined fish and shellfish during storage period.