PurposeThe purpose of this paper is to study the role of social factors that determine the length of stay in a mental hospital and also understand the main factors leading to the phenomena as a step to solve it.Design/methodology/approachA case-control cross-sectional observational study is performed which studies correlates for the lengthy stay in a mental hospital. The study population consists of two groups: Group A (94 patients), taken from the patients hospitalized for more than one year, further subdivided into schizophrenia and schizoaffective inpatient group and bipolar affective inpatient group; and Group B (94 patients), receiving their treatment at the outpatient clinic after being admitted for less than six months, this group was further subdivided into same categories as Group A.FindingsThe study showed that the positive score in positive and negative symptoms scale (PANSS) showed highly statistically significant (p<0.01) correlation with the length of hospital stay for the schizophrenic and schizoaffective patients in the inpatient group. The results showed no statistically significant difference (p>0.05) between the inpatient schizophrenic cases and the inpatient affective cases regarding the length of hospital stay.Research limitations/implicationsThe linear regression model was used to understand the predictors of increased length of hospital stay. The linear regression analyzing the scale data of schizophrenic and schizoaffective patients found that the length of hospital stay for the schizophrenic and schizoaffective patients depends on the patient’s age and his positive PANSS score. On the other hand, linear regression model for bipolar affective patients in the study found no statistically significant attributes of the length of hospital stay.Practical implicationsThe study found that the length of hospital stay for schizophrenic and schizoaffective patients depends on the patient’s age and his positive PANSS score.Social implicationsThe need for this study stems from the large numbers of mental inpatients who have been lengthily admitted in mental health hospitals in Egypt, while trying to understand main factors leading to the phenomena as a step to solve it. The study found that there is a highly significant difference between inpatient group and outpatient group regarding the marital status, education level, and psychosocial class, with inpatient group having more single, illiterate, and very low social class cases.Originality/valueResearch in the area of chronic psychiatric hospitalization and its effect on the course and prognosis of mental illness is still scarce, especially in the Arab world; therefore, the research will open the door for further research efforts in the future with a larger sample of patients to study the pros and cons of deinstitutionalization taking into account the past experience of health systems in other countries.