In the present study we investigated whether the personality trait of assertiveness can be judged accurately, which cues are used to judge assertiveness, and how cue utilization is related to accuracy. We additionally assessed whether perceiver and/or target gender moderate any of these relationships. Participants (72 females and 36 males) watched 33 short videoclips each featuring a female and a male target interacting. After watching each clip, participants indicated how assertive they judged each target to be. Since the self-reported assertiveness measure of the targets was known, accuracy of judging assertiveness could be calculated. Each target was coded on an array of behavioral cues. Results showed that assertiveness could be judged at better than chance level and that female targets were assessed more accurately than male targets. To find out how much perceivers relied on each specific cue to judge assertiveness (cue utilization), perceived assertiveness was correlated with each of the behavioral cues across targets. We found that perceivers used different cues to judge assertiveness in female as compared to male targets. Also, accuracy of judging assertiveness was achieved by using somewhat different cues for male and female targets.