Aim: This in-vitro study aims to assess the acidity of coffee drinks with different combinations and evaluate their pH level in relation to the critical pH of dental enamel (5.5) and dentin (6.7). Methodology: All beverages (black coffee, black coffee with milk, Arabic coffee, and Turkish coffee) were mixed according to the manufacturer's instructions with deionized water and cooled down to room temperature (25ºC). The pH of the solutions was compared with that of the control groups, i.e., 0.3% citric acid and distilled water as positive and negative controls, respectively, at 10mins, 30mins, 1hr, and 2hrs. (0.1N) NaOH solution was introduced to the tested solutions to reach a pH of 8 to evaluate the titratable acidity. Results: Instant black coffee was found to be the most acidic with a pH value of (5.13 ± 0.02), whereas instant black coffee with milk was the least acidic with a pH of (6.20 ± 0.01). Instant black coffee with milk was found to have the highest concentration of titratability with a value of (16.2 ± 0.1) mL of (0.1 N) NaOH, to reach a pH of 8. Conclusion: This in-vitro study showed that the tested solutions can reach the critical pH that can cause enamel and dentin erosion. Also, the data showed little correlation between the pH and titratable acidity titrated to a pH value of 8. MeSH Keywords: Dental erosion, pH level, titratable acidity, enamel, dentin, teeth, coffee.