Ehlers-Danlos syndrome (EDS), a heterogeneous disease of the connective tissues, is diagnosed by a triad of symptoms that include skin hyperextensibility, joint hypermobility and connective tissue fragility. Nephronophtisis (NPH) is an autosomal recessive interstitial nephritis leading to terminal renal insufficiency around puberty. The occurrence of these two rare diseases together is unusual. A review of the literature discloses no case of this association. We report here on a 16-year-old man with undiagnosed EDS, who was referred to our hospital because of renal insufficiency, history of polyuria and polydipsia. Renal ultrasound showed normal kidney size, with a lack of corticomedullary differentiation. Renal biopsy specimen disclosed chronic tubulointerstitial nephritis resembling NPH. Further evaluation identified hypermobile joints and hyperextensible skin, which led to the diagnosis of the EDS. These data suggest that patients with EDS need to be evaluated carefully for the presence of renal anomalies.