BACKGROUND : Pedestrians are amongst the most vulnerable road users and their unsafe behaviors have a major impact on traffic injuries. The aim of this study was to determine the underlying psychological factors behind red light violation in pedestrians' crossing behavior based on the Theory of Planned Behavior (TPB) and to provide recommendations for preventive interventions. METHODS : This qualitative study was conducted in Tabriz, one of the metropolitan cities of Iran. 30 pedestrians were individually interviewed using semi-structured, open-ended questions to elicit salient consequences, social referents, and circumstances regarding pedestrians' red light crossing behavior. The transcribed interviews were analyzed using directed content analysis followed by frequency analysis in order to detect modal salient beliefs. RESULTS : A total number of 115 sub-categories were identified which were then classified in the ten predetermined categories of the Theory of Planned Behavior: advantages, disadvantages, positive feelings, negative feelings, approving referents, disapproving referents, behaving referents, not-behaving referents, facilitators, and barriers. "Saving time" was elicited as the most important both the advantage and the positive feeling. "Getting injured" was identified as the most serious disadvantage. "Lowering the level of culture" was obtained as the main negative feeling. "Friends/Peers" comprise the most prominent group among both the approving and the behaving referents, whereas "Family members" constituted the most significant group both among the disapproving and the not-behaving referents. "Being in a hurry" was introduced as the most substantial facilitator and "The fear of accident" was identified as the most influential deterrent factor. CONCLUSIONS : Based on the major findings, reducing pedestrians' red light violations needs to focus: on the perceived negative and positive consequences and feelings of this behavior like getting injured, and saving time respectively; on the approval role of friends/peers, and the disapproval role of family; and on the fear of accident as a barrier, and rushing as a facilitating factor. More precise quantitative research is needed to determine the predictive power of these factors in such risky behavior.