Background:There is dearth of records on prevalence and spectrum of adult endocrine disorders in Nigeria.Objective:To document the spectrum of endocrine disorders as seen in endocrinology, diabetes, and metabolism (EDM) outpatient clinic, Department of Medicine of Olabisi Onabanjo University Teaching Hospital, Sagamu, Ogun State over a 3-year period.Methods:This was a retrospective study of the medical records of all new consultations seen in the EDM outpatient clinic between January 2016 and December 2018. All endocrinology diagnoses were classified according to the 10th revision of the International Statistical Classification of Diseases and Related Health problems (ICD-10). Information on demographic, source of referral, baseline clinical, and biochemical indices were gleaned and subjected to descriptive statistics using SPSS version 21, and results were presented as proportions (frequencies and percentages) and mean (±standard deviation).Results:Two thousand seven hundred and sixty-five patients were seen and managed at EDM outpatient clinic over the specified time frame. Eight hundred and sixty-three were new cases, age range 16–88, mean of 54.10 (±13.9) years with female preponderance 520 (60.3%) and female-to-male ratio of 1.5:1. The internal referral system constituted the main means of referral to the EDM clinic. The most common endocrine referrals were diabetes mellitus (DM) (697, 80.8%) and thyroid disorders (119, 13.8%) followed by metabolic syndrome (29, 3.36%) and hypothalamic–pituitary disorders (HPOs, 9, 1.04%).Conclusion:The common endocrine cases seen in Sagamu are DM, thyroid diseases, metabolic syndrome, and HPO similar to worldwide trend.