Acute kidney injury (AKI) increases mortality and morbidity of hospitalized patients. We aimed to evaluate the prevalence of AKI, etiology, and associated risk factors among hospitalized patients during the Hajj time. Also to do comparative analysis for the use of slow continuous therapy versus conventional hemodialysis (HD) therapy on the patient outcome. The study was conducted between September 29 and November 25, 2011, inclusive (Islamic lunar dates Dhu'l-Qa'dah 1 to Dhul-Hijjah 29, 1432) at King Abdul-Aziz Hospital, a 250-bed hospital, in Makkah, Saudi Arabia. From 851 patients of 47 different countries were admitted, 87 (10.2%) patients developed AKI with mean age (±standard deviation) of 60.26 (±9.28) years with a male predominance: men constituted 65 (74.7%) and females 22 (25.3%). The major cause for admission was infections accounted for 51.7% (45 patients) of all the admitting patients who developed AKI. Hypertension and diabetes mellitus were the most common underlying comorbidities, present in 61 (70.1%) and 53 (60.9%) patients, respectively. Only 21 (24.1%) patients who developed AKI required replacement therapy (RRT). Fourteen patients (16.1%) received conventional HD, seven (8%) patients received continuous renal replacement therapy and 66 (75.9%) patients did not need RRT. Fifty-two (59.8%) patients had improved renal function on discharge from our hospital, 4 (4.6%) patients were discharged on dependent HD, 5 (5.7%) patients were discharged as chronic kidney disease patients on conservative management and 26 (29.9%) patients died during admission. There was no significant difference on the outcome according to the use or even the type of RRT. Infection was the main cause of admission for patients who developed AKI. The type of RRT used had no different effect on the outcome at time of discharge.