Rencana Pelaksanaan Pembelajaran (RPP) mempunyai fungsi strategis sebagai pedoman dalam pelaksanaan pembelajaran. Pengembangan RPP untuk meningkatkan kualitas pembelajaran banyak dilakukan berdasar model pembelajaran, strategi, media, materi, dan filosofinya. Etnomatematika merupakan hal yang masih baru sehingga pengembangan RPP berbasis etnomatematika yang berfungsi untuk mengenalkan dan mendorong kesadaran budaya masih belum banyak dilakukan. Penelitian ini ingin mengungkap permasalahan dan kesulitan apa saja yang dialami mahasiswa dalam menyusun RPP berbasis etnomatematika dan bagaimana karakteristik produk RPP terkait etnomatematika. Penelitian ini menggunakan studi kasus dengan responden terdiri dari 10 mahasiswa PGSD Universitas Negeri Yogyakarta yang memberikan keterangan mendalam tentang kesulitan yang dialami. Berdasar wawancara mendalam, diperoleh kesimpulan mengenai kesulitan penyusunan RPP antara lain pada aspek: sintaks, metode, dan model, kemudian muncul permasalahan yang esensi yaitu sejauh mana etnomatematika muncul dalam RPP.Case study of student problems in the Elementary School Teacher Education Study Program in compiling an ethnomathematical lesson plan based on the Yogyakarta Palace AbstractThe Lesson Plan has a strategic function as a guide in the implementation of learning. The development of lesson plans to improve the quality of learning is mostly carried out based on learning models, strategies, media, materials, and philosophies. Ethnomathematics is still new, so the development of ethnomathematics-based lesson plans that serve to introduce and encourage cultural awareness is still not widely practiced. This research wants to reveal, what students experience problems and difficulties in preparing ethnomathematics-based lesson plans, and how the characteristics of lesson plans relate to ethnomathematics. This study uses a case study with respondents consisting of 10 Elementary School Teacher Education students at Universitas Negeri Yogyakarta who provide in-depth information about the difficulties they are experiencing. Based on in-depth interviews, conclusions were obtained about the difficulties in preparing a lesson plan, among others, in the aspects: syntax, methods, and models, then the essential problem arises, namely the extent to which ethnomathematics appear in the lesson plan.