The present study aimed to provide an analytical model explaining the relationship between guerrilla marketing, tourists’ purchasing patterns, consumption patterns, and product quality. The statistical population consisted of all tourists who had purchased souvenirs from Sarab County at least once. Based on Krejcie and Morgan’s table, a sample of 384 respondents was selected through convenience sampling. This research is applied in purpose and descriptive–correlational in method. Data were collected using standardized questionnaires, and the hypotheses were tested through structural equation modeling (SEM) using AMOS Graphics software. The findings indicated that guerrilla marketing had a significant direct effect on tourists’ purchasing patterns (β = 0.16). Moreover, it indirectly influenced purchasing behavior through the mediating variables of product quality (β = 0.378) and consumption pattern (β = 0.076). Altogether, the studied variables explained about 40% of the variance in the purchasing pattern. The results suggest that applying guerrilla marketing strategies, particularly in small and medium-sized souvenir businesses, can achieve high effectiveness at low cost by enhancing perceived product quality, shaping consumption patterns, and promoting tourists’ purchasing intentions.