Brain tumors are the most common solid tumor entity in childhood. Symptoms are often unspecific, depending not only on the localization of the tumor, but also on the age of the child. The aim of this study was to detect factors influencing the time span between the occurrence of symptoms and the diagnosis to alert health professionals to the early symptoms of pediatric brain tumors. The records of 245 consecutive patients treated for brain tumors between 1980 and 2004 at the neuropediatric department of the University of Muenster were analyzed regarding their primary symptoms, tumor location, entity, and, in 151 cases, the primary electroencephalogram findings. The median time span between symptom onset and diagnosis in our study was 24 days. Multivariate analysis showed a significant influence of 6 parameters on the interval between symptom onset and diagnosis. An additional symptom had a significant influence on the time span between symptom onset and diagnosis in the univariate analysis. The findings that several symptoms influence the interval between symptom onset and diagnosis emphasize the necessity to systematically inquire about the key symptoms of brain tumors. The challenge for every consultant is to decide in which cases cerebral imaging is appropriate. As the most frequent symptoms are unspecific and often underestimated, a detailed anamnesis is crucial to detect possible brain tumor patients. In doubtful cases, a systematic interrogation regarding the catalogue of symptoms can be helpful.