Tow hundred and ten hens (24 weeks old) and 21 cocks of MATROUH breed were fed on seven treatments for 12 weeks to study the effect of layer diet acidification by HCI or H2504 on the productive performance, egg traits, fertility and hatchability. Treatments used were basal (without acidification), basal plus HCI at 0.21%, 0.42% and 0.84%, or H2SO4 at 0.6%, 1.2% and 2.4%. Results showed that acidification did not show any mortality, diar­rhea and evidence of dehydration. Also, no detrimental effect could be found on feed consumption, productive performance, egg traits, fertility, hatchability. On the other hand, results revealed the effectiveness of HC1 at 0.21% and H2504 at 0.6%, equivalent to 0.06 Moles/kg of the feed, in improving FC with 24.4% and 16.8%, respectively. Insignificant effect of these treatments was found on egg traits, fertility and hatchability as compared to the basal. The effect of HCI was found to be better than H2SO4 in the term of the productive performance. Layers tolerated lev­els of the two acids up to 0.84% HCI and 2.4% H2504_.,