Objective: To investigate the effect of pulsed electromagnetic field (PEMF) on cellular proliferation and osteocalcin production of MG63 human osteoblast-like cells. Methods: MG63 cells were placed in 24-well culture plates in the amount of 30,000 cells/well with 2 ml DMEM media supplemented with 10% FBS. The experimental plates were placed between a pair of Helmoltz coils powered by a pulse generator (PEMF, 50 Hz, and 1.5mV/cm) in the upper compartment of a dual incubator (Forma). The control plates were placed in the lower compartment of the incubator without Helmotz coils. After one week, media were collected and assessed for osteocalcin production using ELISA kits. The cell proliferation was determined by using MTT assay. The data were analyzed using a one-way analysis of variance (ANOVA). Results: MG63 human osteoblast-like cells from the experimental group showed higher rate of proliferation than those from the control group (100% increase, p<0.05). However, no significant difference in osteocalcin production was detected between the two groups. Conclusion: PEMF stimulation effect on MG63 human osteoblast-like cells was most likely associated with increase in cell numbers, but not with the enhancement of osteocalcin production. (Supported by PSU grant 0638/45)