Background Diabetic ketoacidosis (DKA) is a metabolic catastrophe which could occur in any type of diabetes. Even when fundamental key points of DKA treatment had been followed, some differences exist in treatment protocols in each physician, highlighting the need to assess adherence to DKA guideline. Aim This study aimed to examine trend of hospitalized DKA patients and outcomes of treatment over a decade at Theptarin Hospital, a multi-discipline based diabetes center in Thailand . Method A retrospective study of DKA episodes admitted over a 14-year period (2005–2018) was done. Clinical characteristics, laboratory data, type of diabetes, severity of DKA were collected and analyzed. Results A total of 94 DKA episodes occurred in 81 diabetic patients (females 61.5%, mean age 47.4 ± 20.4 years, T1DM 41.5%, T2DM 50.0%, Ketosis-prone diabetes 8.5%, baseline A1C 10.8 ± 3.0%). While infection was the common precipitating factor in T2DM, omission of insulin was the usual precipitating factor in T1DM. During ongoing management, 26.6% of patients developed hypokalemia and supplementation was not prescribed as per protocol in this group of patients. Almost 13% of patients experienced hypoglycemia in the first 24 h. Median time to resolution of DKA was 8.5 h. Four T2DM patients expired from the precipitating cause of DKA which accounted for mortality rate at 4.3% in our study. Conclusions Inadequate metabolic monitoring and iatrogenic hypoglycemia remain areas of concern for DKA management. Occurrence of hypokalemia was related to poor adherence to protocol guidance on potassium supplementation. A strengthened educational program for nursing and medical staffs should be emphasized.