Outflow facility responses to pilocarpine were determined in ten cynomolgus monkey eyes after disinsertion of the ciliary muscle from the scleral spur. The effect of large intravenous dose given on one occasion was compared to the effect of intense topical treatment for 18 to 24 hours on another occasion. The effect of the two modes of treatment differed from eye to eye, but were similar in the individual eye. In some eyes facility rose while in others it fell. The average effect of both treatments was very small.