Mother-child dyads (N = 35) were videoed as they wrote a shopping list in an environmental print-rich grocery shop play setting. The children (M age = 4.3 years) were assessed on emergent literacy skills (letter name and sound knowledge, print concepts, phonological awareness, and letter and name writing). Mothers' general level of print and grapho-phonemic mediation during the joint-writing task was scored. After controlling for child age, maternal print and grapho-phonemic mediation of children's writing were both positively related to letter sound knowledge. Grapho-phonemic mediation was positively related to print concepts. A particular focus of this study was to investigate mothers' natural use of surrounding environmental print to scaffold writing. Only four mothers used environmental print to scaffold their child's writing. These mothers applied a variety of strategies including pointing out letters, describing letter shapes, and encouraging copying of letters and words from product labels and signs. There were no obvious differences between those who did or did not use environmental print in demographic factors, emergent literacy skills, or maternal mediation during joint writing. Despite there being only a small number of mothers who used environmental print, the range of strategies observed highlights the need for further research into using environmental print to scaffold children's emergent writing. (author abstract)