Pemeriksaan laboratorium merupakan pemeriksaan yang sering dilakukan untuk kepentingan klinik. Beberapa pemeriksaan darah yang dilakukan di laboratorium membutuhkan persiapan pasien khusus seperti puasa 10-12 jam. Hal ini akan memberikan hasil yang akurat bagi pemeriksaan darah terkait, namun juga bisa menimbulkan hasil yang kurang akurat bagi pemeriksaan lain. Salah satu pemeriksaan yang juga sering dilakukan yaitu pemeriksaan urine lengkap. Pemeriksaan urine yang dipengaruhi oleh kondisi tubuh puasa yaitu pH dan keton urine. Tujuan penelitian ini untuk mengetahui gambaran hasil pH dan keton urine puasa. Jenis penelitian yang digunakan adalah penelitian deskriptif dengan menggunakan random sampling sebanyak 27 orang. Pemeriksaan pH dan keton urine dilakukan menggunakan carik celup. Hasil pH urine puasa yaitu 5,0 sebanyak 6 orang (22,22%); 6,0 sebanyak 18 orang (66,67%); dan 6,5 sebanyak 3 orang (11,11%). pH urine responden tergolong pH urine asam yang kemungkinan adanya hubungan dengan puasa. Urine pH asam dipengaruhi oleh beberapa faktor diantaranya yaitu kelaparan, diabetes, dehidrasi, asidosis sistemik. Hasil pemeriksaan keton urine puasa didapatkan hasil negatif sebanyak 27 orang (100%). Hasil pemeriksaan keton urine negatif karena menggunakan spesimen urine pagi yang hanya melakukan puasa selama 12 jam. Pada keadaan orang normal pemeriksaan benda keton dalam urine negatif karena semua hasil metabolisme lemak dipecah menjadi air dan karbon dioksida. Pada kondisi puasa atau kelaparan berat dimana terdapat kekurangan karbohidrat sebagai sumber energi, maka badan akan menggunakan cadangan lemak sebagai sumber energi sehingga terjadi peningkatan keton sebagai hasil metabolisme lemak. Laboratory examination is an examination that is often done for the benefit of the clinic. Some blood tests performed in the laboratory require special patient preparation such as fasting 10-12 hours. This will provide accurate results for related blood tests, but can also lead to less accurate results for other tests. One of the tests that is also often done is a complete urine examination. Urine examination is influenced by fasting body conditions, namely pH and urine ketones. The purpose of this study was to describe the results of fasting urine pH and ketones. The type of research used is descriptive research using random sampling as many as 27 people. Examination of urine pH and ketones was carried out using a dipstick. The results of fasting urine pH were 5.0 as many as 6 people (22.22%); 6.0 as many as 18 people (66.67%); and 6.5 as many as 3 people (11.11%). The pH of the respondent's urine is classified as acidic urine pH which may have a relationship with fasting. Urine acid pH is influenced by several factors including hunger, diabetes, dehydration, systemic acidosis. The results of the fasting urine ketone examination showed negative results as many as 27 people (100%). The results of the urine ketone examination were negative because they used a morning urine specimen that only fasted for 12 hours. In normal people, the examination of ketone bodies in the urine is negative because all the products of fat metabolism are broken down into water and carbon dioxide. In conditions of fasting or severe starvation where there is a shortage of carbohydrates as an energy source, the body will use fat reserves as an energy source, resulting in an increase in ketones as a result of fat metabolism.