Diabetes melitus tipe 2 adalah jenis yang paling banyak terjadi dan selalu meningkat setiap tahunnya. Penatalaksanaan secara non farmakologi dapat memperbaiki kualitas hidup dan mengurangi risiko komplikasi salah satunya dengan jus jambu biji merah. Pada 100 gram jambu biji merah terkandung 87 mg vitamin C, 80,38 mg flavonoid, dan 5,2 gram serat. Kandungan antioksidan tersebut dapat menangkal radikal bebas, anti-diabetes dan anti-inflamasi. Tujuan penelitian untuk mengetahui pengaruh pemberian jus jambu biji merah terhadap kadar glukosa darah puasa pada penderita diabetes melitus tipe 2. Penelitian dilakukan di wilayah kerja Puskesmas Kartasura dengan rancangan penelitian one group pretest postest design terhadap 15 sampel. Jenis glukosa darah yang diuji adalah glukosa darah puasa 10 jam dengan metode GOP-PAP. Intervensi diberikan jus jambu biji merah sebanyak 300 mL/hari selama 12 hari. Analisis statistik menggunakan uji Wilcoxon. Rata-rata nilai glukosa darah puasa pretest 178,67 mg/dL dan postest 168 mg/dL. Hasil uji statistik terdapat pengaruh pemberian jus jambu biji merah terhadap kadar glukosa darah puasa dengan nilai P= 0,030 (<0,05). Disarankan untuk peneliti selanjutnya dapat mengendalikan faktor lain yang dapat meningkatkan resiko diabates melitus.Type 2 diabetes mellitus is the most common type and always increases every year. Non-pharmacological management can improve quality of life and reduce the risk of complications, one of which is with red guava juice. In 100 grams of red guava contained 87 mg of vitamin C, 80.38 mg of flavonoids, and 5.2 grams of fiber. The content of these antioxidants can ward off free radicals, anti-diabetic and anti-inflammatory. The purpose of the study was to determine the effect of giving red guava juice on fasting blood glucose levels in patients with type 2 diabetes mellitus. The study was conducted in the working area of the Kartasura Health Center with a research design of one group pretest postest design on 15 samples. The type of blood glucose tested was 10-hour fasting blood glucose by the GOP-PAP method. The intervention was given red guava juice as much as 300 mL/day for 12 days. Statistical analysis using the Wilcoxon test. The average fasting blood glucose value of pretest 178.67 mg/dL and postest 168 mg/dL. The results of statistical tests showed the effect of giving red guava juice on fasting blood glucose levels with a value of P = 0.030 (<0.05). It is recommended that researchers can further control other factors that can increase the risk of diabetes mellitus.