BACKGROUND & AIMS: We characterize the sonographic features of Crohn's disease at diagnosis and evaluate the prognostic value of intestinal ultrasound during the early stage of disease. METHODS: A prospective, population-based cohort of patients with newly diagnosed Crohn's disease were followed with intestinal ultrasound in conjunction with symptomatic, biochemical, and endoscopic evaluations. RESULTS: Between May 2021 and April 2023, 201 patients with adult-onset Crohn's disease were recruited. No associations were found between sonographic inflammation at diagnosis and diagnostic delay. After 3 months, transmural remission was achieved in 38% of patients, with patients with colonic disease achieving transmural remission more often. Transmural remission at 3 months was significantly associated with steroid-free clinical remission at 3 months and all subsequent follow-ups within the first year. Transmural remission was also associated with a lower risk of treatment escalation during follow-up until 12 months (26% vs 53%; P = .003). At 12 months, 41% had achieved transmural remission. Higher baseline body mass index negatively impacted the likelihood of 12-month transmural remission significantly (overweight: odds ratio [OR], 0.34; 95% confidence interval [CI],0.12-0.94; obese: OR, 0.16; 95% CI, 0.04-0.73). The International Bowel Ultrasound Segmental Activity Score (IBUS-SAS) in the terminal ileum at diagnosis was the best predictor of ileocecal resection during the first year, with an optimal threshold of 63 (area under the curve [AUC], 0.92; sensitivity, 100%; specificity, 73%). CONCLUSIONS: Transmural remission is an achievable outcome target for many patients with newly diagnosed Crohn's disease and is associated with a favorable clinical outcome, including sustained steroid-free clinical remission. Further, intestinal ultrasound findings at diagnosis predict future ileocecal resection.