This comparative prospective study of mammalian bites attending one urban Accident and Emergency department before the implementation of the Dangerous Dogs Act 1991 and again 2 years later, was to see the effect of the Act on the pattern of injury. The study comprised a simple questionnaire detailing the injury, the implicated species, and the treatment or referral if applicable. In both groups studied (before and after implementation of the Act) 134 consecutive bites were recorded, contributing 1.2 per cent and 1.23 per cent of total attendances during these respective periods. Dogs were found to bite most commonly: in the pre-legislative group 73.9 per cent were due to dog bites and in the post-legislation group 73.1 per cent. In both groups studied, human bites occurred as the second most common mammalian bite; 17.9 per cent in the pre-legislation group and 12.7 per cent in the post-legislation group. Human bites were as common as those from the most implicated breed of dog. In general human bites were found to require more active treatment and specialist referral. The study demonstrates the vast majority of such injuries are treated within Emergency departments. This study also shows how dangerous breeds compare with others that bite, demonstrating that these breeds contribute to only a small proportion of these injuries. This comparative study clearly demonstrates little impact on rate of attendances for such injuries since the introduction of the 1991 Act. If legislation aims to reduce and prevent injury from animal bites, in its present form it does little to protect the public; this study suggests a wider control of the dog population may be required.