Thirty five patients with anorrectal malformations are reviewed. These are divided in high and low anomalies according to some simple clinical data, better than the drawing of reference lines to determinate the height of puborrectalis muscle. Malformations were associated in 13 cases with urinary tract estructural anomalies and in four cases with isolated vesico-ureteral reflux. Diagnosis of urinary tract infection was made in 14 patients, 12 of them with recto-urinary fistula. A point is made about the complete and early exploration of all these patients to prevent irreparable renal damage that could be developed.