The present study investigated whether psychosomatic reaction to panicogenic CCK 4 administration can be predicted based on basal and pre-administration psychological traits and characteristics. Sixteen healthy volunteers participated in a double-blind, placebo-controlled cross-over experiment in which they were subjected to CCK 4 and placebo challenge. One week prior to experimentation, they completed a battery of self-administered psychological inventories, including the trait form of State-Trait Anxiety Inventory (STAI-T), Chambless Anxious Cognitions Inventory (CACI), Beck Depression Inventory (BDI) and the Symptom Checklist 90 (SCL-90). The state form of STAI (STAI-S) was administered before and after the injections of CCK 4 (25 mg i.v.) and placebo. Various elements of the panic-like experience (latency and duration of symptoms, number and intensity of symptoms, fear of symptoms, and post-administration state anxiety) were recorded after both injections. The results of multiple regression analyses suggest that basal STAI-S, STAI-T and BDI are very good predictors of the number and intensity of CCK 4 -induced symptoms, the fear reaction to panic symptoms and post-injection state-anxiety. The SCL-90 scores were retained as the best predictor of placebo-induced panic-like symptoms. We conclude that substantial portions of variability in CCK 4 and placebo-induced panic-like reaction can be explained by basal psychological characteristics.