The Hall coefficient of aipha plutonium was found to be +2.8 x 10/sup - 13/ at 388 c- K and -6.5 x 10/sup -13/ (v-cm)/(A-G) at 78 c- K. The variation between these extreme temperatures was found to change gradually with temperature and the value changes sign at 190 c- K. No field dependence of Hall voltage was found, nor did the application of 11,500 G affect the resistivity maximum at 100 c- K. It is concluded that the resistivity maximum is not due to magnetic ordering. An observation by Loasby and Taylor that the Hall coefficient changes with time at 77 c- K was not confirmed here. The results were used to calculate the numbers of holes and electrons as a function of temperature on the two-band model. The calculations show that a narrow 5f-6d band and broad 7s conduction band is more likely than a narrow 5f and broad 6d band. (auth)