New psychoactive substances are becoming increasingly common in many parts of the world, and some of them are marketed as “legal highs” and are produced to circumvent the drug legislation, and they come in many unregulated forms. The aim of this research was to characterize the metabolites of a new psychoactive substance and hence provide the fundamental data needed for further research of toxicity and future drug testing. The synthetic cannabinoid 4-fluoro-CUMYL-5-fluoro-PICA was incubated in cryopreserved hepatocytes for 1, 3 and 5 hour and then the formed metabolites was analyzed with an LC-QTOF-MS method, data analysis was performed by using the software MassHunter Qualitative Analysis. For 4-fluoro-CUMYL-5-fluoro-PICA a total of ten metabolites were identified, with three hydroxylations, two oxidative defluorinations to carboxylation, three oxidative defluorination and two fluoropentyl dealkylation. The metabolite with the highest intensity was oxidative defluorination.