Sir,Dengue infection is an important tropical mosquito- borne, acute febrile illness. This infection is considered a common viral infection in the tropical world. In additional to the classical hematological manifestation, there are also other atypical manifestations of dengue. The psychological manifestation is interesting. There are some previous reports on the dengue-induced mania[12] and psychosis.[3] The fatal outcome is also mentioned in those dengue cases with psychological manifestation.[3] The interesting question is why there are very few reports on psychological manifestation in dengue. The first explanation is the possible underreporting due to lack of concern by general practitioner. The second explanation is the lack for clinical association between dengue and psychological problem. The finding in previous case reports might be only accidental co-occurrence. of interest, based on the Thai database from Thailand (Thai Index Medicus) where the highest prevalence of dengue in the world is reported, there is no report on either psychosis or mania among dengue patients.