A new strategy for the simple, environmental-friendly and highly-available microextraction of non-steroidal anti-inflammatory drugs (NSAIDs) from human urine samples has been proposed. The procedure assumes NSAIDs separation from aqueous sample phase via in-situ forming deep eutectic mixtures based on the formation of hydrogen bond between –OH group of menthol and the oxygen atom of –COOH group of NSAIDs. The developed strategy was used for the HPLC-UV determination of ketoprofen and diclofenac in human urine samples. Under optimal experimental conditions limits of detection, calculated from a blank test, based on 3σ were found to be 15 μg L⁻¹ and 44 μg L⁻¹ for ketoprofen and diclofenac, respectively. The microextraction process can reach equilibrium within 1 min with extraction recovery values from 93 to 97% for both analytes.