This study found that the quality of life of problem gamblers in New Zealand (NZ) declined by 54%. Quality of life declined by a smaller degree for moderate-risk (37%) and low-risk gamblers (18%). Gamblers in NZ had larger declines in their quality of life compared to Australian gamblers at the same levels of gambling severity. The impact on quality of life for problem gambling in NZ was comparable to that experienced in severe alcohol use disorder.