Assays of adenosine and its derivatives in biological fluids involve fluorimetric, radioimmunological or chromatographic analyses. Techniques currently used are tedious because they involve either an extraction using immunological methods or one or two freeze drying cycles when using high performance liquid chromatography (HPLC). In this context, we describe a “quick” HPLC method using a diode array detector for the spectral analysis and quantitation of adenosine and its derivatives in less than two hours following sampling. We compared our results to those obtained with an HPLC technique coupled to UV detection.