Objective: In this study we aimed to evaluate factors affecting the length of hospitalization for patients who were hospitalized into Gazi University Hospital Psychiatric Ward in year 2015. Methods: Quantitative data analysis was executed using software program SPSS 21.0, descriptive values were given such as frequency, percent, mean +/- standard deviation. A Pearson's chi-square test was used for cathegorical variables, a Mann-Whitney U test and a Kruskal Wallis Test was used in independent groups lacking normal distribution. Hospital stay time and treatment costs predictions of different features were assessed with logistic regression. The relationship between variables was measured using Spearman's correlation test. Statistical significance level was set as p<0.05. Results: Schizophrenia was the mostly encountered disease in the patient group, followed by depression and bipolar disorder. Among male patients schizophrenia patients was the most while depression patients was the most among female patients. Depression was the mostly seen diagnosis in patients who were married while schizophrenia was the mostly seen diagnosis in patients who were single. It was seen that women had increased length of hospital stay by 1.99 times more than men. Bipolar disorder patients' mean length of hospital stay was the longest, and neurocognitive disorder patients' length of hospital stay was the shortest. Conclusion: As a result, the number of hospital stay increases with age. Women are in hospital longer than men. The patients who stay in the hospital for the longest time are bipolar disorder, schizophrenia and depression patients. The patients who stay in the hospital for the shortest time are somatic symptom disorders, alcohol and drug abuse disorders and neurocognitive disorders patients.