OBJECTIVE: Research describing the personal experiences of Guillain-Barré syndrome (GBS) is limited, but is important for identifying the patients' need of support. The aim of this study was to describe experiences of falling ill with GBS, with the focus on the onset of disease, the diagnosis and the illness progress during hospital care. METHODS: The study included 35 persons, 20-78 years old. They were interviewed 2 years after the onset of GBS. The interviews were analysed using qualitative content analysis. RESULTS: The onset was described as either an incomprehensible, prolonged, increasing deterioration with puzzling sensations or as a frightening, rapid onset with a sudden loss of body control. The majority of the persons relied heavily on the reassurance of a positive prognosis, and expressed immense confidence in being able to recover. During the early phase at the hospital, a rapid and steady course of improvement inspired hope in many persons. In contrast, even in this early phase of hospital care some individuals expressed doubts of a slow recovery. Feelings of fear and insecurity were evident when losing body functions, thus causing helplessness. Sensations of pain, numbness and lost body image increased their vulnerability. Half of the ventilator-treated persons expressed vivid memories of scary hallucinations. CONCLUSION: The onset is characterized by an incomprehensible bodily deterioration or a frightening, rapid paralysis. In the initial phase, there is hope for recovery, which for many individuals is reinforced by a steady recovery. In contrast, early psychosocial support may be necessary for some persons with an alarmingly slow recovery.