Although congenital talipes equinovarus (CTEV) is often idiopathic, additional birth defects occur in some patients that may have an impact on the treatment of this disorder. The purpose of this study was to determine the prevalence of associated malformations, chromosomal abnormalities, or known genetic syndromes, and to compare treatment outcomes of children with idiopathic CTEV with children with non-idiopathic CTEV. Of 357 children evaluated, 273 (76%) had idiopathic CTEV (179 males, 94 females; mean age 2y 1mo [SD 1y 2mo], range 0-18y) and 84 (24%) had non-idiopathic CETV (51 males, 33 females; mean age 2y 5mo [SD 2y], range 0-16y). Disorders affecting the nervous system were found in 46 (54%) children with non-idiopathic CTEV. In a subgroup of patients treated entirely at our institution (n =196), children with non-idiopathic CTEV (n = 47) required more casts for correction than those with idiopathic CTEV (n = 149; 5.3 vs 4.6; p = 0.016). There was also a greater risk of recurrence in non-idiopathic CTEV (14.9% vs 4%; p = 0.009), but no significant difference in the need for extensive surgery (2.7% vs 8.5%; p = 0.096). Treatment was initiated at a mean age of 13 weeks (range 1wk to 2y 6mo) for both idiopathic and non-idiopathic patients, and treatment was assessed during a minimum 2-year follow-up. Non-idiopathic CTEV can be successfully treated with the Ponseti method of serial casting, with low recurrence rates or need for surgery.