This data set contains the martian surface atmospheric pressure readings obtained through much of the duration of the Viking Lander 1 and 2 missions (data are included for Viking Lander 1 sols 0 - 2245 and Viking Lander 2 sols 0 - 1050). The data are derived from the ambient pressure sensor carried onboard the Landers and values are presented on a point by point basis. The sampling rate was variable throughout the mission maximum sampling rate was one measurement per second, but ranged up to 65 minutes for Lander 1 and 105 minutes for Lander 2. For further background information on the Viking Meteorology Instrument System (VMIS) and results from this experiment, see CHAMBERLAIN_ETAL1976, HESS_ETAL_1976A, HESS_ETAL_1976B, and HESS_ETAL_1977. For discussions of analyses of experiment data, see also TILLMAN_1977, HESS_ETAL_1980, and TILLMAN_1988. An earlier version of this data set is archived at the NSSDC (NSSDC ID 75-075C-07D and 75-083C-07D).