Ten patients, aged from 3 to 10 years, who had either had attacks of perception errors of body schema and objects or had visual hallucination were enrolled from 1987 to 1990. Seven were boys and three, girls. The metamorphopsia or visual hallucination that has been named the "Alice in Wonderland syndrome" (AIWS) were the leading presentations. All the patients had preceding episodes of upper respiratory tract infection (URI) from two days to four weeks previously except for one who had had chickenpox within the immediate three days of being seen. Among these patients, six had received serological studies for Epstein-Barr (EB) virus infection. Two patients were indeed victims of acute EB virus infection as documented by positive IgM antibody against EB virus capsid antigen, the other three patients were highly suspected of having had recent EB virus infection as suggested by positive Heterophil antibody test and high IgG antibody titer against EB virus capsid antigen (1:320X). The duration of perception disorder ranged from four days to three months. All cases recovered completely, without sequelae. It is emphasized that any young children who present as acute episodes of AIWS should undergo examination for EB virus infection. The neurological outcome of AIWS seems to be good.