The 13‐70 kev emission from the 0.7s X‐ray pulsar SMC X‐1 was monitored by the UCSD/MIT instrument aboard HEAO‐1 during three ‘‘80‐day epochs in 1977 and 1978. The X‐ray flux wandered slowly between a maximum value and unobservably small levels with a rough time scale of 60 days. This pattern resembles, but is less regular than, the ‘‘1 month cycles of Her X‐1 and LMC X‐4, which are attributed to regular occulation by a tilted precessing accretion disk. Alternatively, the data also resemble band‐limited red noise, which then would imply a highly variable accretion flow. There is no evidence for cyclotron lines in the spectrum.