Research on integrated writing tasks is increasing, while there is a paucity of empirical findings on graph-based writing, as one type of these tasks. The present study purports to examine the contribution of L2 writing anxiety to university students' graph writing performance and the strategies they employ for these tasks. The participants of this study were 209 undergraduate university students who wrote an essay on a graph-based prompt and completed two questionnaires measuring writing anxiety and the use of graph writing strategies. The results of structural equation modelling (SEM) indicated that writing anxiety negatively predicted graph writing strategy use and performance. Besides, graph comprehension, graph interpretation, and graph translation, as the latent variables of graph writing strategy use, were found to be positive predictors of graph writing performance. Pedagogical implications with regard to improving performance on graph-based prompts are offered.