This study investigated length of stay (LOS) for patients who died in hospital in Southern Thailand from 2000 to 2003 with respect to principal diagnosis and demographic, geographic and hospital size factors. The computerized data of 40,498 mortality cases were obtained from the Ministry of Public Health from 167 hospitals in 14 provinces of Southern Thailand between October 2000 and September 2003 with information on age, gender, principal diagnosis, province and hospital size. Logistic and linear regression with log-transformed LOS was used to analyze the data. Patients with injuries as principal diagnosis had shortest LOS, whereas cancer patients had the longest LOS. Older patients, particularly females, had higher LOS for all diagnoses. LOS increased with hospital size except in the North and North West. Small hospitals in the South West region had the lowest LOS whereas large hospitals in the North West had the highest. The highest proportion of bed days (11.2%) occurred in males aged less than 60 diagnosed with infectious diseases. Males aged less than 60 diagnosed with injuries and digestive diseases, and aged at least 60 diagnosed with COPD, and aged less than 60 diagnosed with infectious diseases, accounted for more than double those for female patients in the same disease groups. Both logistic regressions with LOS at least 1 week as the outcome and linear regression on appropriately log transformed LOS gave consistent results. Providing suitable palliative care or allowing patients to select the place for spending their final time of life, especially for patients with chronic diseases, which can reduce hospital resource utilization.