Abstract: Apparatus for effectively ejecting a protective cover from the elongated probe of a medical thermometer, even in cases where the cover can stick to the probe surface. The probe cover, which includes a generally cup-shaped body and a resilient ring at the body's open end, is secured in place on the probe by an outwardly-projecting flange at the probe's base end, which retains the probe cover's circular ring. An ejector sleeve reciprocates between a retracted position, in which it is retracted from the elongated probe, and an extended position, in which it fully encircles the probe. A coil spring continuously biases the ejector sleeve to its extended position, but with a force nominally insufficient to free the probe cover's resilient ring from the probe's retaining flange.