In Borneo, the weather does not follow annual patterns in either temperature or precipitation. It is therefore unclear whether or not we should expect insects to follow seasonal patterns of occurrence, as they tend to do in non-tropical regions. We examined the occurrence of 129 chrysomelid species during a 34-month period on the Universiti Malaysia Sabah campus located in northern Borneo, to investigate whether their occurrence follows seasonal patterns. For the majority of species, there was no tendency for adults to appear during a particular time of year. For some species, adults were collected in nearly every month of the year. Our findings suggest that most Bornean chrysomelid species do not follow seasonal patterns of occurrence.