Purpose: This study aimed to explore the effects of task-based language teaching (TBLT) with a tour guide simulation as a focused activity on young Thai learners' English speaking skills and their attitudes towards the instruction. Methodology: Based on a three-phase framework (i.e., pre-task, during-task, and post-task), TBLT was implemented with a Grade 4 class for a period of eleven weeks. Initially, a set of English lessons developed based on the context of local tourist attractions was implemented at the pre-task stage. In the second stage, a simulated tour guide task was used to assess learners' ability to turn the language input into practical and authentic use of spoken English. Subsequently, corrective feedback on each student's performance was provided, and their attitudes towards the instruction were examined at the last stage. Findings: The students were able to satisfactorily complete the tour guide task in English, indicating the potential of the task as a device to strengthen their speaking skills. Moreover, they generally had a favourable attitude towards the instruction. Significance: These findings are significant for both school teachers and curriculum designers. In addition to confirming the effectiveness of TBLT, this study highlights the promising use of context specific-based lessons and class activities as an avenue for young learners to practice speaking English in a context relevant to them.