At present the only information available on the effectiveness of the cannabis crop eradication programme in New Zealand is the total number of cannabis plants destroyed each year. These figures can only provide a very crude measure of the effectiveness of these operations. A better measure would be the percentage of total cannabis production destroyed--known as the drug seizure rate. This paper calculates the seizure rate of the cannabis crop eradication programme in New Zealand using the amount of cannabis reported consumed in the Alcohol and Public Health Research Unit's (APHRU) National Drug Survey. The seizure rate for the 1998 programme is calculated to be 26-31%. This compares favourably with drug seizure rates reported in other countries. The effectiveness of the cannabis crop eradication programme, and its apparent modest share of the total cannabis control budget, raises some intriguing questions about the role an expanded crop eradication programme could play in a future cannabis control strategy.