The performance of the Analyst® passive sampler for the measurement of formaldehyde and acetaldehyde was assessed in a series of field experiments. It consists of a polyethylene cylinder filled with silica gel or a Florisil® adsorbent and a stainless steel or a silver anti-turbulence net which works as an ozone scrubber. Indoor and outdoor formaldehyde and acetaldehyde concentrations were measured in different locations (offices and rooms of a public building, a car, laboratories and private homes) of Ciudad Real (Spain) and Rome (Italy). In some cases, Radiello® passive samplers were used along with Analyst®, in order to compare and validate the results. The performance of the Analyst® device was also assessed by checking some parameters such as the diffusive sampling rate of acetaldehyde and the storage stability after collection and the self-consistency for both formaldehyde and acetaldehyde. From this work, it can be concluded that the Analyst® sampler is suitable for measuring formaldehyde and acetaldehyde in indoor and outdoor air.