The present study was undertaken to investigate the activities of paraoxonase in acute mushroom poisoning cases. This investigation was made between June 2009 to June 2010 with 64 mushroom poisoning patients who admitted to our emergency department in which we analyzed the 6 and 48 h paraoxonase 1 (PON 1) levels. Mean value of PON1 A(6 h) was 74.83 +/- 41.68 U/ml and PON1 B(48 h) 91.90 +/- 51.08 U/ml. The difference was statistically significant (p = 0.001) Mushroom poisoning cases, which are a public health problem, are frequently reported in Europe, United States, and in the Far East. Paraoxonase levels can be used as prognostic markers for acute mushroom poisoning.