Acute kidney injury is very common in hospitalized patients and has been described in up to twenty percent of admissions. Although there are many causes of acute kidney injury, one of the more overlooked causes is the antibiotic prescribed during these admissions. In this article we discuss the two main causes of antibiotic induced kidney injury illustrated by two cases, one of ciprofloxacin Kristal nephropathy and of ciprofloxacin tubule-interstial nephritis. We discuss the pathophysiology, most common involved antibiotics, diagnostics and the treatment.