Historically multi-nodular goiters have been thought of as a benign disease with a low risk of associated malignancy. Recent studies suggested that the incidence of malignancy in patients with MNG is not uncommon. With the aim of determining frequency of malignancy in multi-nodular goiter this cross sectional observational study was done at Mymensingh Medical College Hospital, Mymensingh, Bangladesh from June 2021 to March 2022. One hundred (100) cases were selected by purposive sampling. Data were collected by preformed questionnaire, clinical examination and laboratory investigations which included only patients with Multi-nodular Goiter (MNG). Analysis was performed using the SPSS software version 23.0. Malignant neoplasm accounted 12 in 100 cases of multi-nodular goiter. Among them 7.0% were Papillary thyroid carcinoma (PTC) and 5.0% were Follicular thyroid carcinoma (FTC). Others (88.0%) cases were non- neoplastic or benign lesion. Age of the patients and duration of multi-nodularity found statistically significant for development of malignancy. As an indicator of probable benign disease multi-nodularity of goiter should no longer be considered. So, multi-nodularity of the goiter should not be considered as low risk of malignancy and delay for surgical intervention.