Recently, changes in consumer demand, the acceleration of innovation, and increasing competition have made increasing customer purchasing power a prominent challenge for companies, forcing them to search for new marketing strategies [1]. In this context, co-branding, which combines the value of two brands to promote a single product, has been considered as a marketing strategy [2]. Co-branding is a marketing strategy in which two or more brands are simultaneously presented to the consumer as a single product in such a way that the total brand assets are greater than the assets of the individual brands. The goal of co-branding is to create synergy, increase awareness, and increase the value of the brands involved by transferring associations from one brand to another and differentiating them from competitors [3]. In this regard, the present study aimed to investigate the effect of co-brand awareness on purchase intention through the mediation of brand image, trust, and brand attachment. The moderating role of customer support was also examined. This research is applied in terms of purpose and, on the other hand, in terms of data collection and analysis method, it is descriptive-survey type. The statistical population of this research is all people who have experience buying from sellers of these products of cooperative companies of Khuzestan province. According to Cochran's formula for unlimited population size, 384 people were determined as a statistical sample and were selected using the available non-probability method. Finally, after processing and refining the questionnaires and removing outliers and incomplete samples, the responses of 349 respondents were used for statistical analysis and testing the hypotheses. A standard questionnaire was used to collect data, the validity of which was confirmed by the face validity method and its reliability by Cronbach's alpha coefficient. To analyze the data, structural equation modeling technique with partial least squares approach was used using SmartPLS software version 3. Results showed that Co-brand awareness through brand trust influences customers' purchase intention. However, this path was not confirmed through mental image. Also, the effect of mental image and brand trust on purchasing intention was confirmed through the mediation of brand attachment. Finally, it was found that customer support for the brand only moderates the effect of co-brand awareness on brand trust, but it does not play a moderating role in the effect of co-brand awareness on mental image. Overall, the results of this study show that co-brand awareness leads to purchase intention when it passes through the path of brand trust and attachment, and this process is intensified or weakened by the level of customer support. From a scientific perspective, this study contributes to the enrichment of the co-branding literature by presenting an integrated cognitive-relational-affective model and shows that focusing solely on cognitive constructs is not enough to explain consumer behavior. The findings also have practical implications for cooperative managers who, despite focusing on increasing co-brand awareness, should also focus on strengthening trust, creating emotional attachment, and creating a platform for customers to express and strengthen brand support in order to be able to increase purchase intention.