Abstract Objectives To compare the effectiveness of early intensive treatment (EIT) versus escalation treatment (ESC) in a nationwide observational cohort of almost 1000 people with relapsing–remitting multiple sclerosis (RRMS). Materials and methods The EIT cohort started with alemtuzumab (AZM), cladribine (CLAD), fingolimod (FTY), natalizumab (NTZ), ocrelizumab (OCR), or ozanimod (OZA); whereas, the ESC cohort was escalated from dimethylfumarate (DMF) or teriflunomide (TERI) to AZM, CLAD, FTY, NTZ, OCR, or OZA within the Austrian MS Treatment Registry. Patients had to stay on therapy for at least 3 months and up to 16 years. The EIT cohort included 743 and the ESC cohort 227 RRMS patients. We used multinomial propensity scores for inverse probability weighting in generalized linear (GLM) and Cox proportional hazards models to correct for the bias of this non-randomized registry study. Results Estimated mean annualized relapse rates (ARR) were 0.09 for EIT and 0.4 for ESC patients. The incidence rate ratio (IRR) in the GLM model for relapses showed a decreased relapse probability of 78% for the EIT versus ESC cohort [IRR = 0.22, 95% CI (0.16–0.30), p < 0.001]. Analyzing the time to the first relapse by Cox regression, a hazard ratio (HR) of 0.17 [95% CI (0.13–0.22), p < 0.001] revealed a decreased risk of 83% for the EIT group. Regarding sustained Expanded Disability Status Scale (EDSS) progression for 12 weeks, a HR of 0.55 [95% CI (0.40–0.76), p < 0.001] showed a decreased probability of 45% for the EIT cohort. Conclusions ESC treatment after DMF and TERI revealed a higher relapse and EDSS progression probability compared to EIT in Austrian RRMS patients. Therefore, an early intensive treatment should be started in patients with an active or highly active disease course.