In patients with bladder dysfunctions, intermittent catheterisation is a bladder evacuation technique with a low complication rate. Therefore, it is regarded as the method of choice in the treatment of chronic residual urine, mostly due to a hypo- or acontractile detrusor. Regarding the incidence of urinary tract infections and urethral strictures, aseptic catheterisation seems to be superior to the clean technique. There are, however, no independent, prospective, controlled, randomised, double-blinded studies comparing the different catheter types. Thus, the question of which catheter is the ideal one cannot be answered yet. Predominantly in patients who have to perform intermittent catheterisation for good, the prevention of long-term complications, especially of the upper urinary tract, is of the utmost importance. In the long run, using an inadequate technique and catheters not optimally designed will clearly lead to a higher complication rate. Despite the lower prices of certain catheters, treatment of these complications will lead to higher instead of lower costs. The data available today clearly demonstrate that aseptic intermittent catheterisation is the technique of choice today. Important details of this treatment modality, however, have to be elucidated by prospective studies in the future.