Behavioural analytic techniques were used to assess the efficacy of a repellent to the house sparrow (Passer domesticus). The repellent, using a combination of olfactory and visual cues, is aimed at deterring birds from roosting sites where faecal contamination may result in disease transmission to humans and animals, and damage to public and private property. In this experiment, four methods of measuring avoidance by sparrows to a commercially available avian repellent were trialed in aviaries and in the field. In initial experiments, the number of sparrows was recorded in predetermined zones across an aviary, and faecal counts were measured as the position of the repellent varied. In further experiments, food removal was recorded when repellent was placed at varied distances from food sources to test the effect of proximity on sparrow feeding behaviour in the aviaries and in the field. There was no apparent repellent effect of this commercially available product, indicating birds were insensitive to any intended aversive properties of its odour or visual appearance. Therefore, as formulated, the product is unlikely to be of any use in a practical setting. Development of chemical repellents based primarily on olfactory cues might be challenging and require additional aversive stimuli.