In 2004, we studied the life history and ecology of a population of Pardosa sierra (Araneae, Lycosidae) from Cave Creek Canyon (Chiricahua Mountains, Arizona). Peak abundance for immatures occurred in July, September, and October. About 64% of all adult males and females were observed in April and May. Females were observed carrying egg sacs between 5 April and 3 August. Diet composition consisted primarily of beetles (18.4%), flies (15.3%), and ants (12.2%). Spiders were active during the day, as well as at night. Immatures and adults preferred sandy or rocky substrates, respectively. Under controlled laboratory conditions, the life cycle consisted of 9 instars, and mean carapace width increased from 0.66 mm (instar 1) to 2.26 mm (instar 9: adult males and females). Clutch size ranged from 35 to 92 (mean = 67.81). Gestation period ranged from 22 to 27 days (mean = 24.06). Significant positive correlations were found between female mass and size, offspring mass and size, female size and clutch size, and female size and clutch mass. Mean total clutch mass was 34.9% of mean female mass.