The lack of fundamental statistical information on the number and nature of cats entering and exiting shelters creates difficulty in understanding the extent of the unwanted and stray cat problem. The aims of this study were to describe the characteristics of cats entering Queensland RSPCA shelters and identify risk factors for euthanasia after entry. Data for all cats entering Queensland RSPCA shelters from January 2006 to December 2007 were obtained from the RSPCA electronic database, ShelterMate©. Data collected included year of intake, category of age at entry, gender, postcode of origin, method of admission to shelter (stray, owner relinquished, council, euthanasia requested, returned, transferred in), breed, and outcome (euthanised, adopted, fostered, reclaimed, transferred out). Univariable and multivariable logistic regression was conducted to identify risk factors for euthanasia. In the study period 26,125 cats entered Queensland RSPCA shelters; 66% were adult cats and 34% were kittens. The most common admission source was stray (50% of adult cats and 69% of kittens), followed by relinquishment (22% of adult cats and 15% of kittens). When age was categorised into adult (> 6 months) and kittens (= 6 months) differences in risk of euthanasia were evident. Age category was strongly associated with the risk of euthanasia; odds of euthanasia were 6.9 (95% confidence interval: 6.4 - 7.5) times higher in kittens than adult cats (P <0.001) after adjusting for year, gender, postcode, admission source and breed. These results show that although kittens comprise approximately one-third of entries to shelters, they are much more likely to be euthanised than adult cats. It is not clear from these results what additional factors relating to kittens may be responsible for increasing euthanasia risk. Further studies collecting the precise age of kittens at entry are required to better elucidate the relationship between age at entry and risk of euthanasia.