Purpose To investigate the effectiveness of conservative therapy for spontaneous isolated iliac artery dissection (SIIAD). Methods From February 2006 to May 2016, all patients with SIIAD were included and analyzed. The diagnosis of SIIAD was made based on contrast-enhanced computed tomography. The imaging morphologic characteristics, treatments, and outcomes for each patient were analyzed. Results A total of 11 patients (10 male and 1 female, age 71.1 ± 7.8 years) were included in this study. Of the 11 patients, 8 patients were asymptomatic and the SIIADs were discovered during the course of computed tomography for other diseases, and 3 patients were symptomatic. Initial computed tomography findings: iliac arterial calcification ( n = 7); compression of the true lumen ( n = 6), with stenosis of the true lumen from 25% to 50% ( n = 3) and ≥ 50% ( n = 3); thrombosed false lumen partially ( n = 4), and no thrombosis in false lumen ( n = 7); dissecting aneurysm ( n = 11); entry points ( n = 11); re-entry points ( n = 1); no dissection extended to the internal iliac or common femoral artery. Conservative treatment was performed in six patients, and the remaining five patients need no treatment. During 23.3 ± 14.2 months follow-up, none recurred symptoms and signs of symptomatic SIIAD; partial remodeling of SIIAD was achieved in four patients, and the remaining seven patients with no change of SIIAD. There was no presence of new false lumen enhancement on contrast-enhanced computed tomography during follow-up. Conclusions SIIAD without arterial rupture or lower limb necrosis can be safely treated with conservative therapy.