Abstract: A spring-loaded latching mechanism for a peristaltic pump that automatically sets and maintains a desired roller head tension. The spring-loaded latching mechanism includes a pair of counter-rotating latching cams positioned on opposite sides of a pump housing. Each latching cam has an indented or slotted portion for engaging a disposable tubing cassette. The disposable tubing cassette includes a length of flexible tubing supported by a circular race or channel. The latching cams are spring-loaded and, when the disposable tubing cassette is inserted into the pump housing, the latching cams urge the disposable cassette with its length of flexible tubing and circular race against a pump roller head to provide the desired roller head tension.