Peak nucleate boiling fluxes for liquid oxygen near 1 atm, have been measured on a 0.75-in.–diameter flat polished horizontal platinum surface located in a known, variable magnetic-field gradient that produced steady acceleration (which could be maintained indefinitely) on the oxygen acting in opposition to the earth's gravitation, gE. Measurements were made under condition ranging from net negative (directed away from the heated surface) accelerations of −0.03gE acting on the bulk liquid to the normal accelerations, 1.0gE. The results indicate that at zero g conditions for the bulk liquid, the peak nucleate boiling flux is ∼0.55 of the value at 1.0gE. For bulk-liquid accelerations ranging from ∼0.25 to 1gE, the experimental results confirm the ¼ power dependence of peak flux on acceleration as predicted by various correlations. However, below 0.25gE the peak flux becomes insensitive to the acceleration, varying approximately in proportion to the 1/14 power of the net acceleration. At bulk-liquid conditions of zero g (±0.005gE) the peak plux breaks sharply and falls by a factor of 10 between zero g and −0.03gE (for this apparatus).