During the summer of 2006 in the paediatric ward of the Spaarne Hospital in Hoofddorp, the Netherlands, a large number of children were admitted with a coxsackievirus type-B infection, one of the enteroviruses. A total of 27 children were diagnosed with this virus. Patient A, a one-month-old boy, was admitted with fever. The spinal fluid showed a high leukocyte count. He was treated with amoxicillin, ceftriaxon and acyclovir, and recovered rapidly. The spinal fluid culture was positive for coxsackievirus type B5. Patient B, a 3-year-old girl, presented with attacks of abdominal pain and groaning respiration. Infection parameters were mildly elevated. The chest X-ray was normal. She was admitted for observation and recovered spontaneously. Viral faeces culture revealed coxsackievirus type B4. Rapid recognition of an enterovirus infection is important to prevent unnecessary diagnostic and therapeutic interventions. PCR is a diagnostic technique of great importance.