The current study aimed to investigate the tendency to use temporal markers (TMs) in English writing by three different levels of Thai writers. Data used in this study were based on the Corpus of Thai Writers of English. The corpus size of approximately 8,800,000 words consisted of essay writing produced by intermediate and advanced student writers and professional writers from two Thai English newspapers. Fraser's (2005) taxonomy of temporal markers was used as an analytical framework. Microsoft Excel was used to calculate the frequency of occurrences, while a Statistical Package for the Social Sciences (SPSS) was the primary research tool for data analysis. A one-way ANOVA reveals a statistical difference in the use of TMs among three groups of writers (p =0.000). The intermediate and professional writers were found to prefer using temporal markers at a comparable ratio. However, the intermediate group used temporal markers in a more diverse attitude than the advanced ones. Six temporal markers ("as soon as," "immediately," "meantime," "meanwhile," "originally," and "subsequently") were hardly utilized in writing by all groups of writers. However, no significant differences were found regarding preferences on the position of the TM in the sentences. The findings improve teaching and learning of cohesive devices, especially temporal markers, in EFL writing classes.