CQ Cephei. Is the period really changing?

The light curves of primary minimum of the eclipsing Wolf-Rayet star CQ Cep have been observed in 5300 A continuum light. The midtimes of the eclipses have been combined with earlier data in order to put new limits on any period change. The last 45 yr data are consistent with no period change, but values for the annual fractional period change as large as a few 10 to the -7th are allowed within the accuracy of the determination. Attempts to model the compatibility between the mass loss rate, a few 10 to the -5th solar masses/year, and the small period change, show that only a very restricted range of specific angular momentum values are compatible with the data. The earliest eclipse epochs are not compatible with the later data, suggesting some change in behavior about 50 yr ago. Detailed features in the light curve are associated with second contact in the eclipse and there is evidence for variable obscuration on both orbital and suborbital time scales.