This case control study was carried out in the Department of Biochemistry, Mymensingh Medical College, Bangladesh in cooperation with the Outpatient Department and Medicine Units of Mymensingh Medical College Hospital, Fulbaria Upazilla Health Complex, Mymensingh and some DOTS centers of BRAC, a non-government organization during the period of July 2006 to June 2007. The aim of the study was to explore the status of serum calcium level in smear positive Bangladeshi pulmonary tuberculosis patients. A total of 120 people of different age groups were included in this study. Subjects were divided into two groups - Group I (Control; n=60) apparently healthy people selected matching by age, sex and socioeconomic status with the cases and Group II (Case; n=60) people with smear positive pulmonary tuberculosis. Serum calcium was estimated by colorimetric principle. Serum calcium was adjusted by serum albumin concentration. Statistical analysis was done by using SPSS windows package. Among the groups, mean±SD of adjusted serum calcium in Group II (2.41±0.15mmol/L) was significantly higher (p<0.001) than that in Group I (1.85±0.11mmol/L). It is evident from the study that serum calcium level significantly increases in smear positive Bangladeshi pulmonary tuberculosis patients.