The purpose of this study was to describe the mastery of maxims of quantity and maxims of quality in Indonesian speech in children with intellectual disabilities. In this study, a qualitative descriptive research method was used. The data source of this research is one child with intellectual disability aged 9;0. The data of this research are words, phrases, and sentences that contain maxims of quantity and maxims of quality. The data collection used in this study includes observation, fishing, recording, and field notes. The stages of data collection are making observations, recording speeches, transcribing speeches, and validating data. In analyzing the data, the pragmatic equivalent method was used. Data analysis procedures include reducing data, interpreting data, and concluding. Based on data analysis, it can be concluded that children with intellectual disabilities have been able to master the maxim of quantity and maxim of quality. L’s speech is able to show its contribution to the speech partner to show the maxim of strength by speaking not excessively and maxim of quality by speaking according to reality. The maxim of quantity and maxim of quality shown by L are still dominated by one word even though L's speech seems to be able to use multi-words. However, the maxim of quantity and maxim of quality used by L still suffer from imperfect pronunciation of sounds such as [r] is pronounced as [l], and the sound [s] which is located at the beginning and middle of the word is replaced with [t]. In addition, L is still unable to use affixes so that he experiences an affix deficit.   Abstrak Tujuan penelitian ini adalah mendeskripsikan penguasaan maksim kuantitas dan maksim kualitas dalam tuturan bahasa Indonesia pada anak disabilitas intelektual. Dalam penelitian ini, digunakan metode penelitian deskriptif kualitatif. Sumber data penelitian ini adalah satu anak disabilitas intelektual berusia 9;0. Data penelitian ini adalah kata, frasa, dan kalimat yang mengandung maksim kuantitas dan maksim kualitas. Pengumpulan data yang digunakan dalam penelitian ini meliputi observasi, pemancingan, perekaman, dan catatan lapangan. Adapun tahap-tahap pengumpulan data adalah melakukan observasi, merekam tuturan, mentranskrip tuturan, dan memvalidasi data. Dalam penganalisisan data, digunakan metode padan pragmatik. Prosedur penganalisisan data meliputi mereduksi data, menginterpretasi data, dan menyimpulkan. Hasil analisis data menunjukkan bahwa anak disabilitas mental sudah mampu menguasai maksim kuantitas dan maksim kualitas. L sudah mampu menggunakan maksim kuantitas dengan bertutur tidak berlebihan dan maksim kualitas dengan bertutur sesuai kenyataan. Maksim kuantitas dan maksim kualitas yang ditunjukkan L masih didominasi dengan satu kata meskipun tuturan L terlihat sudah mampu menggunakan multikata. Akan tetapi, maksim kuantitas dan maksim kualitas yang digunakan L masih mengalami kekurangsempurnaan pelafalan bunyi seperti [r] dilafalkan menjadi [l], dan bunyi [s] yang terletak pada awal dan tengah kata diganti dengan [t]. Selain itu, L masih belum mampu menggunakan afiks sehingga mengalami defisit afiks.