During investigations of 2-oxy-pyrrolidine-acetamide (piracetam, Nootrop) the influence on the cyclic adenosine monophosphate (cAMP) level was measured. 20 guinea pigs (inbred albinos) were used for the investigations. 6 animals served as a control group, 14 animals were treated daily for 16 days with 35 mg piracetam/kg b.w. The cAMP concentration was determined in the frontal brain and intestine. The animals treated 16 days with piracetam showed an increase of cAMP in the frontal brain of 134% compared with untreated animals. In the intestinal tissue, the difference between the control group and the piracetam-treated animals ranged around 84%.