Subclinical mastitis (SCM) is an asymptomatic worldwide udder infection that results in substantial losses to the dairy industry. Our main objective was to evaluate and compare the clinical performance of 4 commercially available screening tests for diagnosing SCM. Foremilk samples were collected from 428 quarters of 107 apparently healthy lactating cows and buffaloes from El-Menofia governorate from 2020 to 2022. Quarter somatic cell count (SCC) was estimated using the FOSS-BacSomatic^® counter and the California Mastitis Test (CMT), with SCM defined as SCC > 200,000 cells/mL. Milk pH was measured cow-side using an AD11^®pH-meter and BOVIVET^® indicator paper. Bacterial cultures of foremilk samples were used to diagnose SCM as a reference method based on the isolation of the causative pathogens. The tests' performance was evaluated by calculating test sensitivity (Se), specificity (Sp), and accuracy at the optimal-cut-point for each test. FOSS-BacSomatic^® counter was the best-performing test for diagnosing SCM (Se = 0.967, Sp = 0.943, accuracy = 0.957) at an optimal-cut-point of >200,000 cells/mL. For comparison, CMT is the second best-performing test at an optimal-cut-point of a non-negative score (Se = 0.892, Sp = 0.878, accuracy = 0.887). The test performance of the AD11^® pH-meter and BOVIVET^® indicator paper was fair, however, the AD11^® pH-meter performed better than the BOVIVET^® indicator paper with Se = 0.807, Sp = 0.845, and accuracy = 0.822. We concluded that the FOSS-BacSomatic^® counter and CMT are considered good tests for diagnosing SCM. On the other hand, milk pH doesn't provide a clinically useful method for diagnosing SCM. However, based on cost, availability and analysis time, there doesn't seem to be a persuasive reason to select the FOSS-BacSomatic^® counter over the traditional CMT to diagnose SCM.