Sulphate, as sulphuric acid, was fed to Shaver 288 and Warren Studler SSL laying hens for 280 days at levels equivalent to 0.2, 0.4, 0.6, 0.8 and 1.0 g sulphate kg-l diet. The results obtained were compared with those found using similar diets to which the sulphate was added as copper sulphate pentahydrate (CuSO4. ~H z O ) .Addition of HzS04 had no effect on food intake, food conversion efficiency, body-weight or egg production. The addition of CuSO4 caused adverse effects on food intake, egg production and body-weight. The HzS04 had no effect on liver, kidney, oviduct, ovary and gizzard weight per unit body-weight. CuSO4 decreased ovary and oviduct weights and increased gizzard weight. HzS04 had no significant effect on liver copper (Cu) concentrations but CuSO4 increased liver Cu. The highest level of CuSO4 addition depressed liver lipid concentration in the Shaver 288 birds. Both the HzS04 and the CuSO4 affected the levels of individual fatty acids.