Formaldehyde (FA) is commonly used in detergents and cosmetics as an antimicrobial and preservative. This substance is toxic to humans and dangerous to health as it causes eye and skin irritation. FA determination is, therefore, a very important quality control parameter. This study developed gas chromatography/mass spectrometry (GC/MS) and solid‐phase microextraction (SPME) with on‐fiber derivatization to determine FA in cosmetic cream skin. FA was derivated using 2,4‐dinitrophenylhydrazine in an aqueous solution. FA in cosmetic cream samples was extracted through SPME fibers in the headspace and rapidly derivated with 2,4‐dinitrophenylhydrazine on SPME fibers. The average detection and quantification limits were at least 0.036 and 0.12, respectively. The results showed that GC/MS and SPME with on‐fiber derivatization are simple, fast, sensitive, and solvent‐free methods for aldehydes determination in cosmetic cream.