Introduction: Hepatocellular carcinoma (HCC) carcinogenesis is not yet fully known. Insulin-like growth factor-1 receptor (IGF-1R) can translocate to the nucleus and modulate cellular growth, possibly participating in HCC development and aggressiveness. This study aimed to evaluate the immunoexpression of IGF-1R in HCC, the cellular compartment involved, and its association with clinicopathological parameters and clinical outcomes. Methods: Liver specimens from 111 HCC patients who underwent liver transplantation or partial surgical resections at a Brazilian referral hospital center were studied. IGF-1R expression was determined by immunohistochemistry, clinical data were collected from medical records, and pathological parameters were obtained from path review. Results: IGF-1R nuclear expression was higher in the tumor than in the adjacent cirrhosis (p < 0.001). The odds of IGF-1R expression in the nucleus compared to the membrane are lower in the cirrhosis condition than in the tumor, suggesting an increase in the prevalence of nucleus expression relative to the membrane from cirrhosis to tumor. There was an association between IGF-1R nuclear expression in HCC and the moderate/poor grade of histologic differentiation (p < 0.001). However, long-term clinical outcomes were not associated with IGF-1R nuclear expression. Conclusion: The data presented here suggest the role of IGF-1R in HCC progression and carcinogenesis as its expression increases in the nucleus relative to the membrane, from cirrhosis to tumor, and it was associated with a poorer differentiated tumor grade. Further research is awaited to fully understand the mechanisms underlying this association.