Long term benefit of carotid angioplasty and stenting (CAS) can be reduced by recurrent stroke related to in stent restenosis (ISR). An individualised predictive tool is needed to identify ISR events. A nomogram for individual risk assessment of ISR ≥ 70% after CAS is proposed. A national observational, prospective, multicentre registry was conducted between January 2015 and December 2020. Cohorts of patients with symptomatic or asymptomatic severe carotid stenosis who underwent CAS were included with a follow up of at least 1 year after CAS. Duplex ultrasound was used to assess in stent restenosis. Pre-operative factors were compared between the non-ISR and ISR groups. Kaplan-Meier and Cox regression were used for variable selection. The nomogram was formulated and validated by concordance indices and calibration curves. An in stent restenosis risk table was generated for risk stratification. A total of 354 patients were included in the analysis. The ISR rate of ≥ 70% was 7.6% (n = 27). Peripheral arterial disease (hazard ratio [HR] 3.18, 95% confidence interval [CI] 1.23 - 8.24, p = .017), anterior communicating artery absence (HR 3.38, 95% CI 1.27 - 8.94, p = .016), diabetes mellitus (HR 3.34, 95% CI 1.21 - 9.26, p = .020), female sex (HR 2.99, 95% CI 1.04 - 8.60, p = .041), and pre-procedure pathologic ultrasound vasoreactivity (HR 3.87, 95% CI 1.43 -10.50, p = .008), as independent risk factors for ISR of ≥ 70%, were included in the nomogram. Concordance index at 12 and 24 months was 0.83. In low risk groups, ISR of ≥ 70% occurred in 4.8% of patients during follow up compared with 56.2% of patients in the high risk groups (p < .001). The nomogram and risk evaluation score have good predictive ability for ISR. They can be used as practical clinical tools for individualised risk assessment.