Structure optimizations were performed for 1 and 2 monolayers (ML) of Fe on a 5-ML W(110) substrate employing the all-electron full-potential linearized augmented plane-wave method. The magnetic moments were also obtained for the converged and optimized structures. We find significant contractions ( 10% ) for both the Fe-W and the neighboring Fe-Fe interlayer spacings compared to the corresponding bulk W-W and Fe-Fe interlayer spacings. Compared to the Fe bcc bulk moment of 2.2μB, the magnetic moment for the surface layer of Fe is enhanced (i) by 15% to 2.54μB for 1 ML Fe/5 ML W(110), and (ii) by 29% to 2.84μB for 2 ML Fe/5 ML W(110). The inner Fe layer for 2 ML Fe/5 ML W(110) has a bulklike moment of 2.3μB. These results agree well with previous experimental data.