Abstract Background: Alzheimer’s disease (AD) is the leading cause of dementia. Currently, no definitive diagnostic test for AD exists. Cerebrospinal fluid (CSF) concentrations of amyloid β (Aβ1-42) peptides and total tau proteins (T-tau) may serve as biomarkers for AD. Aim: The objective of this study was to investigate the usefulness of CSF Aβ1-42 and T-tau analyses in the diagnosis of AD with Tunisians. Methods: We focused on three groups originating from Central Tunisian that matched in age (range 48–85): healthy controls (n = 53), AD patients (n = 93) and non-Alzheimer (nAD) dementia (n = 35) patients. Aβ1-42 and T-tau levels were measured in CSF by sandwich enzyme-linked immunosorbent assay. Results: The ratio of T-tau/Aβ1-42 at baseline yielded a sensitivity of 85.3% for detection of AD and the specificity was 84.8% to differentiate controls and nAD dementia. Conclusion: Our findings confirm the use of T-tau/Aβ1-42 ratio in the discrimination of AD patients from all other patients.