Ultraviolet spectroscopy of LSI + 61 303*

New IUE low-resolution spectoscopy of the X-ray/radio source LSI + 61 303 is presented and discussed, and previously reported data critically reassessed. There is no strong evidence for continuum variability; in particular, eight spectra covering the 1200–1950 Å region show a scatter of only ∼ 3 per cent. There is some variability in the emission lines, possibly related to the star's shell activity. The C IV resonance doublet reveals a stellar wind with a terminal velocity of ∼ 1400 km s⁻¹. The data are consistent with a $$10 R_\odot, T_\text{eff}\simeq15 500$$ K star at 2.3 kpc, reddened by E(B–V) = 0.75.