BACKGROUND: In the aftermath of Hurricane Katrina, widespread flooding devastated the New Orleans healthcare system. Prior studies of post-hurricane healthcare do not consistently offer evidence-based recommendations for re-establishing patient care post-disaster. The primary objective of this study is to examine associations between patient characteristics, chief complaints, final diagnoses, and medications prescribed at a post-Katrina clinic to better inform strategic planning for post-disaster healthcare delivery (e.g., charitable donations of medications and medical supplies). METHODS: This study is a retrospective chart review of 465 patient visits from 02 September 2005 to 22 October 2005 at a post-Katrina clinic in New Orleans, Louisiana that was open for seven weeks, providing urgent care services in the central business district. Using logistic regression, the relationships between patient characteristics (date of visit, gender, age, evacuation status), type of chief complaint, final diagnosis, and type of medication prescribed was examined. RESULTS: Of 465 patients, 49.2% were middle-aged, 62.4% were men, 35% were relief workers, and 33.3% were evacuees; 35% of visits occurred in week five. Of 580 chief complaints, 71% were illnesses, 21% were medication refill requests, and 8.5% were injuries. Among 410 illness complaints, 25% were ears, nose, and throat (ENT)/dental, 17% were dermatologic, and 11% were cardiovascular. Most requested classes of medication refills for chronic medical conditions (n = 121) were cardiovascular (52%) and endocrine (24%). Most illness-related diagnoses (n = 400) were ENT/dental (18.2%), dermatologic (14.8%), cardiovascular (10.2%), and pulmonary (10.2%). Thirty-six percent of these diagnoses were infectious. Among 667 medications prescribed, 21% were cardiac agents, 13% pulmonary, 13% neurologic/musculoskeletal/pain, 11% antibiotics, 10% endocrine, and 9.3% anti-allergy. The likelihood of certain chief complaints, diagnoses, and medications prescribed varied with patient characteristics. CONCLUSIONS: Donations of certain classes of medications were more useful than others. Prevalence of select co-morbidities, the nature of patient involvement in recovery activities in the disaster area, and post-disaster health hazards may explain variations in chief complaints, diagnoses, and medications prescribed by patient characteristics.