The objective of this study was to observe parent–child interactions in tiendas, limited assortment food stores catering to Latinos in the United States, and to examine the extent to which child involvement influenced these interactions and their purchase outcomes. Two confederates, one posing as a tienda employee and one posing as a customer, observed the entire shopping trip of 100 Latino parent–child (mean age = 8 years) dyads and coded the following: number and type of parent- and child-initiated request interactions, types of purchase influence attempts used by children and how parents responded, and whether the product was purchased. Level of child involvement was examined as a potential influencing factor on purchasing. The observations were relatively short (mean duration of 10 minutes), reflecting the “quick trip” nature of the observed shopping trips. From the 100 parent–child dyads, 144 request interactions were observed, and among dyads with at least 1 request interaction during the shopping trip, the average number of request interactions per dyad was 2. Children initiated most of the request interactions by asking for a product or simply placing it in the basket; parents initiated 24% of the request interactions. Child involvement in shopping and checkout were associated with spending and purchase outcomes. These results indicate that children and parents influence each other during grocery shopping, and children who are more involved have greater influence over purchases. Furthermore, this study identified a number of targets for future family/parent and consumer food environment interventions.