Environmental variables can affect performance of global positioning system (GPS) telemetry; however, similar assessments have not been reported for Argos satellite telemetry. We used a stratified random design and linear mixed-effects models to evaluate the influence of 2 environmental variables (canopy cover and topographic obstruction) on 2 metrics of Argos satellite telemetry performance, observation rate and mean location error. Our results indicated that an Argos transmitter moving from minimal (i.e., 20%) to maximal (i.e., 95%) topographic obstruction and canopy cover would experience, on average, only a 12.4% decrease in observation rate (approx. 1.3 fixes/24 hr of operation), and mean location error would decrease by 3.4% (7.8 m). We concluded that these environmental variables have little practical effect on Argos telemetry performance, a finding that markedly contrasts similar evaluations of GPS telemetry. We documented a substantial increase in the number of high-quality locations compared with values reported previously in the literature; this is likely due to recent improvements in satellite and transmitter technology. Although Argos telemetry location errors continue to exceed those reported for GPS telemetry, the system should be considered as a telemetry tool when avoiding data bias associated with missed fixes is more important than location accuracy. © 2012 The Wildlife Society.