Summary: Background: The Transient Perivascular Inflammation of the Carotid artery (TIPIC) syndrome is presumably a very rare disease characterized by a local transient inflammation of the tissue around the carotid artery. Its pathophysiology remains unknown. We performed an updated study of TIPIC syndrome cases in the setting of a multinational collaborative study. Methods: This study was conducted as an observational multinational retrospective individual patient level cohort study. Information from all known cases diagnosed with TIPIC syndrome in the literature (2005–2020) was collected after a semi-structured literature search of PubMed and Web of Science. We also collected unpublished information of patients from French, Swiss, and Italian vascular medicine or radiology departments. Results: A total of 72 patients were included and served for data analysis: 42 (58.3%) were women; the mean age was 47.9 (SD=11.4) years. Symptoms were unilateral in 92% of patients and 81.4% required pain killers. At baseline, irrespective of the imaging method used, the median thickness of the carotid lesions was 5 (Q1–Q3: 4–7; range: 2–11) mm and the median length of the lesion was 20 (Q1–Q3: 10–30; range: 3–50) mm. We found a positive linear correlation between thickness and length. At follow-up, the thickness of the carotid lesions decreased to a median of 2 (Q1–Q3: 1–3; range: 0–6) mm; the length decreased to a median 10 (Q1–Q3: 5–15; range: 0–41) mm. A linear correlation between baseline and follow-up values was observed for both thickness and length measurements. Symptoms disappeared after a median of 14 (Q1–Q3: 10–15) days. Thirteen patients experienced a recurrence after a median follow-up of 6 (Q1–Q3: 2–12) months. Conclusions: The present analysis elucidates clinical and sonographic characteristics of TIPIC syndrome, indicating the benign nature of this condition. A future international registry will study the long-term course of the disease.