Immigrants attempting to cross the border often wander for days without food or water, subsequently developing acute kidney injury (AKI) secondary to rhabdomyolysis. In this article, we describe our experience with myoglobinuric AKI in these border crossers. Records from all patients in the custody of the border patrol from 1 June 2010 to 30 June 2011, who had AKI defined by the Acute Kidney Injury Network (AKIN) criteria and a CK > 1000 IU/L, were reviewed. The age, gender, temperature, days in the desert, initial serum creatinine, CK on presentation, need for dialysis, length of hospital stay, and serum creatinine at discharge were recorded and analyzed. Forty-two patients developed myoglobinuric AKI with a mean age of 32.5 years. Among them, 38 were males and four females. There was a mean of 4.2 days in the desert. Seven had stage 1 AKI, 10 stage 2, and 25 stage 3. 5 patients required hemodialysis. Only one patient had a temperature >100.6ºF on arrival. CKs ranged between 1101 and 447,966 IU/L. Mean length of stay was 4 days. Two patients were discharged on hemodialysis and eight were discharged with serum creatinine levels of >1.3 mg/dL. This is the largest series of myoglobinuric AKI reported in border crossers. The kidney injury is presumably due to the excessive heat combined with volume depletion. We have coined the term "border crossers' nephropathy" for this disorder. This is a serious problem that has both political and economic consequences on both sides of the border.