DL-Mandelic acid is widely used as an antimicrobial agent, particularly in the treatment of urinary tract infections due to its ability to be excreted through the kidneys and act directly in the urinary tract. It functions as a urinary antiseptic by inhibiting the growth of bacteria such as Escherichia coli and Proteus species. The compound is effective in both acidic and neutral urine, making it suitable for long-term use with minimal disruption to normal flora.

In the pharmaceutical industry, DL-mandelic acid serves as a chiral building block in the synthesis of various racemic drugs, especially those requiring α-hydroxy acid structures. It is also used in dermatology and cosmetic formulations for its mild exfoliating and skin-lightening properties, making it beneficial in treating acne, hyperpigmentation, and improving skin texture.

Additionally, it finds application in analytical chemistry as a resolving agent for separating enantiomers of basic compounds due to its chiral nature. In industrial settings, it acts as a corrosion inhibitor and is used in metal cleaning and plating processes.