The retention, UV absorbance, and electrochemical response of adenosine and some of its precursors and metabolites under varying mobile phase composition was investigated using a UV detector on line with an electrochemical detector. The primary interest was focused on adenosine. Experimental retention data sets of this compound obtained on two columns in buffered mobile phases of different pH values modified with methanol and/or acetonitrile were fitted through adequate equations. The physical meaning of the fitted parameters was discussed, besides the dependence of these equation coefficients on the type of organic modifier and composition of mobile phase. The possibility of predicting the retention behaviour of adenosine on the basis of a limited number of data was also explored.