BACKGROUND: Elevated inflammatory markers such as C-reactive protein (CRP) are associated with worse outcomes in patients thrombolysed for acute ischemic stroke (AIS). AIMS: To investigate whether changes in CRP levels are associated with neurological change after thrombolysis for AIS. METHODS: Retrospective analysis of a single-center database of consecutive thrombolysis cases for AIS from October 18, 2011, to June 15, 2015, inclusive. Multivariate regression analysis was used to investigate the relationship between change in CRP 12-24 hours after thrombolysis and change in NIHSS (National Institutes of Health Stroke Scale) score 24 hours after thrombolysis. The other potentially confounding predictor variables included in the model were CRP on admission and NIHSS score before thrombolysis. RESULTS: Complete data were available for 108 out of possible 435 eligible patients. Increases in CRP levels 12-24 hours after thrombolysis were negatively associated with reduction in NIHSS score 24 hours after thrombolysis (coefficient .08, 95% confidence interval .031-.129, P = .002). Thus, on average, for every 12.5 mg/L additional increase in CRP 12-24 hours after thrombolysis, NIHSS score at 24 hours improved by 1 point less. CONCLUSION: While it was previously known that elevated CRP levels are associated with worse outcomes in patients thrombolysed for AIS, the current work demonstrates that changes in CRP levels after thrombolysis also relate to neurological change, and thus may have scope for use as prognostic markers.