Keadaan umum lemah, badan kurus, tekanan darah tinggi, anemia, gatal di kulit, warna kulit menjadi lebih gelap, mual adalah tanda tidak adekuatnya hemodialisis secara klinis. Berdasarkan telaah literatur didapatkan sembilan faktor yang berpengaruh langsung terhadap adekuasi dialisis yaitu body mass index (BMI), jenis akses vaskular, lama hemodialisis, frekuensi hemodialisis, kecepatan aliran darah, ultrafiltrasi rata-rata, luas permukaan dializer, jenis heparinisasi, dan hematokrit. Penelitian bertujuan untuk mengetahui prediktor dominan terhadap adekuasi dialisis pada pasien hemodialisis di Rumah Sakit PKU Muhammadiyah Yogyakarta berlangsung dari bulan Mei–Juni 2013. Studi potong lintang dilakukan pada 90 responden secara purposive sampling. Adekuasi dialisis dihitung dengan rumus Kt/V. Semua data diambil pada sesi kedua hemodialisis. Data dianalisis menggunakan uji regresi linier ganda. Diperoleh adekuasi dialisis rata-rata 1,36±0,377. Terdapat hubungan yang bermakna adekuasi dialisis dengan BMI dan jenis heparinisasi. Tidak terdapat hubungan yang bermakna jenis akses vaskular, kecepatan aliran darah, ultrafiltrasi rata-rata, hematokrit, lama hemodialisis, frekuensi hemodialisis, dan luas permukaan dializer dengan adekuasi dialisis. Simpulan, faktor dominan yang memengaruhi adekuasi dialisis pada pasien hemodialisis adalah BMI dan jenis heparinisasi. [MKB. 2015;47(1):29–34]Kata kunci: Adekuasi, body mass index, hemodialisis, prediktorPredictor of Dialysis Adequacy in Hemodialysis Patients in PKU Muhammadiyah Hospital YogyakartaWeakness, thin appearance, , high blood pressure, anemia, itches, darkened skin color and nausea are the clinical signs of inadequate hemodialysis. Based on literature reviews, there are 9 factors that directly influence the adequacy of hemodialysis; body mass index (BMI), vascular access, length and frequency of hemodialysis, blood flow rate, ultrafiltration rate, dialyzer surface area, heparinization, and hematocrit. This study aimed to study the dominant predictor of dialysis adequacy in hemodialysis patients in PKU Muhammadiyah Hospital Yogyakarta. Cross sectional study was done involving 90 respondents through purposive sampling method. The hemodialysis adequacy was assessed using the Kt/V formula. All data were collected during the second session of hemodialysis. Data were examined using double linier regression. The ,ean dialysis adequacy was 1.36±0.377. The statistic test result revealed a significant correlation between dialysis adequacy and BMI and the type of heparinization. There was no significant correlation with the type of vascular access, blood flow rate, ultrafiltration rate, hematocrit, length and frequency of hemodialysis, and dialyzer surface area with dialysis adequacy. In conclusion, the dominant factors influencing dialysis adequacy on hemodialysis patients are  BMI and type of heparinization. [MKB. 2015;47(1):29–34]Key words: Adequacy, body mass index, hemodialysis, predictors DOI: 10.15395/mkb.v47n1.410