Whether task-irrelevant emotional stimuli facilitate or disrupt attention performance may depend on a range of factors, such as emotion type, task difficulty, and stimulus duration. Few studies, however, have systematically examined the influence of these factors on attention performance. Sixty-three adults, scoring within a normative range for mood and anxiety symptoms, completed either an easy or difficult version of an attention task measuring three aspects of attention performance: alerting, orienting, and executive attention. Results showed that in the easy task only, threatening versus nonthreatening task-irrelevant emotional faces facilitated orienting regardless of stimulus duration. These effects were no longer significant during the difficult condition. When the easy and difficult conditions were examined together, duration effects emerged such that stimuli of longer durations lead to greater interference, although effects were nonlinear. Findings illustrate that threat-relevant emotional stimuli facilitate attention during tasks with low cognitive load, but underscore the importance of considering a range of task parameters. Results are discussed in the context of adaptive and maladaptive emotion-attention interactions.