Methylene blue is used as a diagnostic and therapeutic agent in humans. Adverse reaction to the dye is very rare. But when adverse reaction occurs it can be very severe and dangerous. The reaction may be local or generalized and sometimes life threatening and can be even fatal. This should be kept in mind to avoid or minimize the severe reactions to the dye. We hereby present a female patient who developed severe chemical peritonitis with small bowel perforations to the methylene blue dye in the course of investigation for primary infertility.