This study investigated the relationship between panic symptoms during remission and subsequent relapse of panic disorder. Research subjects were 169 individuals, enrolled in the Harvard/Brown Anxiety Research Project, who were in episodes of panic disorder at intake and remitted during the 8-year follow-up period. Panic symptoms during remission were examined as predictors of panic disorder relapse. For the relapses that did occur, we report the level of symptomatology during the previous 4 weeks. Depending on symptom severity and whether or not the relapse included agoraphobia, panic symptoms during remission were associated with an approximate two- to threefold increased risk of relapse. However, on examination of symptoms during the 4 weeks before relapse, we found that the majority of relapses were preceded by no panic symptoms. Thus, although panic symptoms during remission may indicate an increased risk of subsequent relapse, the absence of symptoms during remission does not indicate that relapse is unlikely.