Introduction: To determine the levels of spinal cord injury (SCI) on free insulin- like growth factor-1 ( IGF-1) content in the bladder and the possible role of free IGF-1 in growth in hypertrophic bladders in an experimental model. Materials and Methods: The contents of free IGF1 and protein in paraplegic and non- paraplegic rats which was induced experimentally by SCI were measured. The wet weights of the bladders were also determined. The results gained were compared. Results: The mean bladder free IGF- 1 level in paraplegic rats was significantly higher than the corresponding bladder free IGF-1 level in sham-operated bladder (p < 0.05). Mean wet weight bladder in paraplegic rats was signifi cantly higher than the sham-operated rats (p < 0.05). Paraplegic bladder had a signifi cantly higher mean protein content than the sham-operated bladder (p < 0.05). Serum free IGF-1 levels in the two groups were not different. Conclusion: Our pilot study reveals that free IGF-1 may be effective in SCI. Copyright (c) 2005 S. Karger AG, Basel.