Objective: Significant developments occurred in the clinical management of acute lymphoblastic leukemia (ALL) in adults in recent decades. However, treatment results are still not satisfactory, especially in routine practice. The objective of this study was to evaluate the general clinical features, treatment details, and outcomes of a large group of patients followed in multiple centers in Turkey with a diagnosis of ALL. Materials and Methods: A retrospective analysis of the data of patients with ALL was made, the patients having been diagnosed and treated between January 2003 and June 2017 by different protocols in the hematology clinics of ten different centers. A total of 288 patients, aged between 17 and 76 years old, were included in the study. In this retrospective multicenter analysis of patients with ALL, classification of patients was performed based on treatment period, Philadelphia chromosome positivity, treatment regimen, and administration of allogeneic hematopoietic stem cell transplantation (allo-HSCT). Results: The majority of cases were B-cell in origin, while 224 patients had B-ALL and 64 of the patients had T-ALL. Median follow-up duration for all patients was 18.2 months (range: 0.03-161 months). Philadelphia chromosome positivity was determined in 49 patients (21.9%), and 54 patients (18.8%) were receiving allo-HSCT. After induction chemotherapy, 219 patients (76.0%) achieved complete remission, 32 patients (11.2%) were evaluated as treatment refractory, and 37 patients (12.8%) were deceased. Median overall survival was 47.7 months (95% confidence interval: 36.1-59.2) and median disease-free survival was 23.4 months (95% confidence interval: 6.7-40.0) for all patients. Conclusion: Multicenter studies are extremely important for defining the specific clinical features of a particular disease. The results of this study will make a significant contribution to the literature as they reflect real-life data providing valuable information about the Turkish ALL patient profile.