We report on five children (three female and two male, age span 11-16 years) with laboratory-supported definite multiple sclerosis or clinically definite multiple sclerosis, diagnosed on the basis of Poser and Paty criteria. All patients were subjected to serial clinical examinations, magnetic resonance investigations, CSF biochemical and immunological studies, and neurophysiological and neuropsychological assessments. Four of the five examined subjects underwent steroid treatment. Over a period of 3 years relapses have been observed in three of them. The first symptoms and signs of multiple sclerosis may be subtle and misleading; careful assessment of them may be crucial for an early diagnosis of the disease.