Purpose. Our lab has found that the autocrine cytokine, Interleukin-1α (IL-1α), acts as a central mediator controlling expression of a number of genes which determine the repair fibroblast phenotype, including collagenase (CL) and Interleukin-8 (IL-8), IL-1α also controls expression of its own gene in an autoregulatory feedback loop. In this study, we investigate the role of the actin cytoskeleton in regulating the IL-1α signalling cascade. Methods. We used early passage cultures of rabbit corneal fibroblasts for these studies. In addition, two rabbit fibroblast cell lines were used (HIG and HIGRA), the latter constitutively expressing Interleukin-1 receptor antagonist. Results. Disruption of the actin cytoskeleton by cytochalasin B (CB) substantially increased IL-1α (10-fold) and CL (5-fold) mRNA levels in HIG cells. The effect of CB was greater than that of exogenous IL-1α (3-fold). Neither cytoskeletal disruption nor the addition of exogenous IL-1α induced CL or IL-1α in HIGRA cells. The HIGRA cells are also unable to express IL-8, which is regulated by IL-1α and defines the repair fibroblast phenotype, Interestingly, when both CB and IL-1α were added to HIGRA cells, IL-1α mRNA levels (500-fold) and CL mRNA levels (10-fold) soared above controls. Using a selective plating technique, we created a population of corneal myofibroblasts expressing α-smooth muscle actin. These cells were resistant to shape change in response to agents that disrupt the actin cytoskeleton and exhibited reduced levels of IL-1α and CL mRNA. Conclusion. These findings suggest that the actin cytoskeleton modulates the repair fibroblast phenotype by regulating activity of the IL-1α autocrine loop, enhancing autocrine signalling when disrupted and inhibiting it when intact.