Introduction: Readmission to hospital because of the impact on the cost and quality of hospital care and Impose an additional burden on the healthcare system, Is an important priority for hospital managers. The aim of Study Was causes of readmission patients toxicological ward of the loghman hakim hospital, Research in Tehran.

Method: This is an applied cross-sectional retrospective study. Research community included Admissions in 1393 in toxicological ward of the loghman hakim hospital. Research Size based on Morgan is 300 clinical records. Sampling Method was simple randomly. Readmission in the present study in hospitalized form was more than one defined. Demographic data includes (age, gender, marital status, occupation, education and variables related to hospitalization (hospitalization Frequency, length of stay, and poisoning quality, discharge situation, referral and insurance) by means of information form was extracted from records. In two level Descriptive statistics (frequency and percentage) and inferential statistics (correlation chi-square test, dependent T test and Chi-square test) were analyzed using SPSS21 software and hypothesis testing was done.

Finding: During the study period300 readmission cases were hospitalized in toxicological ward of the loghman hakim hospital.13/4% patient was readmission. The readmission cause in 41/6% patient was related to family issues. It Can be named respectively emotional, spiritual, and addiction with regard to other topics. The total cost of treating patients was 206521754 Rials. The average cost of stay per patient 10256639 Rials, payment by patient 928136 Rials, and Subsidies health payment by health ministry was 1834370 Rials.

Conclusion: The results of this study showed that, several factors may be involved in readmission to hospital patients poisons ,the most important of them can be mentioned in the four ares of family problems, emotional problems, mental problems and addiction.