Moving rats from their home cages to a different environment for a twenty minute period tended to raise plasma glucose levels (PGLs). In general, the more different the novel environment was from the housing condition, the greater the rise in PGL. Stimulus contexts that have led to conditioned hyperglycemia in previous experiments caused a larger rise in PGLs than stimulus contexts that led to conditioned hypoglycemia in previous experiments. These glycemic effects of environmental novelty did not habituate across seven exposure periods. Experiment 2 showed that chlordiazepoxide (CDP) reduced PGLs in animals transported to novel environments. Experiment 2 also showed that conditioned hyperglycemia occurred when insulin was administered in the environment that led to the highest PGLs in Experiment 1, and that conditioned hypoglycemia occurred in this same environment when the animals were regularly pretreated with CDP. Administering insulin in an environment that did not initially elicit a large rise in PGL resulted in a tendency towards conditioned hypoglycemia that was not influenced by CDP.