Introduction and importance: The coexistence of Hashimoto’s thyroiditis and ulcerative colitis has been previously mentioned, as these diseases are autoimmune diseases. Limited data about the coexistence of rheumatoid arthritis in patients with Hashimoto’s thyroiditis have been published till now. Meanwhile, the coexistence of Sjogren’s syndrome during the course of rheumatoid arthritis is well known. The coexistence of Hashimoto’s thyroiditis, Sjogren’s syndrome, and ulcerative colitis has also been reported in rare cases. Case presentation: A 32-year-old female, with a 10-year history of Hashimoto’s thyroiditis, 4 years of rheumatoid arthritis, and 2 years of secondary Sjogren’s syndrome, presented to our Rheumatology Department, complaining of fatigue, weight loss, intermittent abdominal pain, and bloody diarrhea for the last 6 weeks. Her colonoscopy findings were compatible with a diagnosis of ulcerative colitis. Clinical discussion: Multiple autoimmune syndromes are defined as the presence of three or more autoimmune diseases in the same patient. They have an increased frequency in patients with a previous history of another autoimmune disease, and a higher correlation with females. The prevalence is rare and was documented only by two systematic reviews, with the rest being separate case reports. Autoimmune thyroid disease and Sjögren’s syndrome were the most frequent diseases encountered, followed by rheumatoid arthritis, and systemic lupus erythematosus. The presence of these autoimmune diseases together suggests that they share a common pathological and physiological genesis. Conclusion: This is the first case report, to our knowledge, that describes the coexistence of Hashimoto’s thyroiditis, rheumatoid arthritis, Sjogren’s syndrome, and ulcerative colitis within 10 years, without a positive family history or psychological stress. Therefore, further studies and long-term surveys are needed to identify other factors that can contribute to the coexistence of these rare diseases.