Developing lesson plans is a complex process that imposes teachers to master in attaining the target goal of teaching and learning. This study explores an EFL pre-service teacher's experience in making lesson plans during the teaching practicum program. This research utilizes qualitative data from diaries. The finding shows the pre-service teacher’s experience in making lesson plans during the teaching practicum program and the challenges she encountered. This study divides the experience into four stages: (1) the preparation stage, this stage reveals the experiences while collecting sources of information before creating lesson plans, (2) the planning stage, this stage reveals the experiences during creating lesson plans, (3) the implementation stage,  this stage reveals the experiences during implementation of lesson plans for the learning and teaching process, (4) the reflection stage, this stage reveals the experience when reflecting the process of making lesson plans. The finding also shows that the challenges I encountered during developing lesson plans consisted of: (1) learning objective, (2) learning procedure, (3) and evaluation. Implications for supervisor teachers, university teachers, institutions, and other pre-service teachers are suggested.