A catheter connection adapter is provided which allows for a user-friendly and mistake-proof connection of a multiple lumen catheter from a dialysis patient to a source of dialysis fluid. The connection adapter contains at least two ports, e.g., one for inflow and one for outflow, and may have a tapered gap between the ports so that an interference fit is made when the ports are inserted into the catheter. In addition, the ports may have a unique key and lock configuration with the catheter such that a fit can only be made when the catheter lumens and the ports are in proper alignment, and the ports may be unconnected to one another so as to provide separate fluid paths for inflow or outflow. The connection adapters are advantageous in that they will allow a multiple lumen catheter to be manually connected to other dialysis equipment following implantation in a patient.