The pattern of serum Thyroglobulin levels in thyroidectomised patients with differentiated thyroid carcinoma (DTC) was studied in retrospect. The serum thyroglobulin (Tg) levels during follow up after initial therapy, in remnant disease, association with metastasis and recurrences were evaluated. Serum thyroglobulin mean values of 4.78±0.4 ng/ml were observed in 37 subjects with successful initial therapy and no residual disease. In the group of subjects with residual disease serum thyroglobulin levels were 35.80±8.1 ng/ml. In contrast, patients with documented metastasis had serum thyroglobulin ranging from 20-1000 ng/dl with a mean of 470±369 ng/ml (n=23). Statistically significantly high values were noted in the group of subjects with metastasis at admission (n=6) and those with recurrence and metastasis (n=8) after a disease free period of 6 yrs (2-17 years) their mean values ranged from 403.85±311 ng/ml to 608±395 ng/ml respectively. In DTC with recurrence in the remnant (n=9) with a mean duration of 3.5 years following successful therapy the serum thyroglobulin levels were 159±102 ng/ml. In all the above subjects the serum thyroglobulin values profiled were over the accepted normal range of 0-10 ng/ml. This retrospective study reiterates the premise that thyroglobulin measurements provide a sensitive and pragmatic parameter in treatment and follow up of patients with differentiated thyroid carcinoma.