Forty three patients with purulent pyelonephritis complicated with abscess or pyelonephritis received local treatment with application of active carbon drainage columns made of macroporous capron net or cotton with 2.5-4 nm pores. These drains showed high efficacy both in vitro and in patients with purulent pyelonephritis. The amount of liquid evacuated from the retroperitoneal space by these drains is 10 times more than that evacuated by chlorvinyl tube. Active carbon in the column adsorbs microbial bodies and toxins from the retroperitoneal space and the kidney. Measurement of mid-molecular peptides (MMP) in patients of the study and control groups detected a sharp fall of serum MMP in the study group. The number of microbial bodies in the study group diminished from 10(10) CFU/ml to 10(3) CFU/ ml, then to 10 CFU/ml; in the controls this number decreased from 10(10) CFU/ml to 10(4-5) CFU/ml on day 7-8. Secondary nephrectomy was performed in 2 (5%) patients of the study group and in 5 (12%) patients of the control group. Lethality (2%) was only in the control group.