Numerous in vivo studies on the ketogenic diet, a diet that can induce metabolic conditions resembling those following extended starvation, demonstrate strong outcomes on cancer survival, particularly when combined with chemo-, radio- or immunological treatments. However, the therapeutic application of ketogenic diets requires strict dietary adherence from well-informed and motivated patients, and it has recently been proposed that hemodialysis might be utilized to boost ketosis and further destabilize the environment for cancer cells. Yet, plasma ketones may be lost in the dialysate—lowering blood ketone levels. Here we performed a single 180-min experimental hemodialysis (HD) session in six anesthetized Sprague–Dawley rats given ketogenic diet for five days. Median blood ketone levels pre-dialysis were 3.5 mmol/L (IQR 2.2 to 5.6) and 3.8 mmol/L (IQR 2.2 to 5.1) after 180 min HD, p = 0.54 (95% CI − 0.6 to 1.2). Plasma glucose levels were reduced by 36% (− 4.5 mmol/L), p < 0.05 (95% CI − 6.7 to − 2.5). Standard base excess was increased from − 3.5 mmol/L (IQR − 4 to − 2) to 0.5 mmol/L (IQR − 1 to 3), p < 0.01 (95% CI 2.0 to 5.0). A theoretical model was applied confirming that intra-dialytic glucose levels decrease, and ketone levels slightly increase since hepatic ketone production far exceeds dialytic removal. Our experimental data and in-silico modeling indicate that elevated blood ketone levels during ketosis are maintained during hemodialysis despite dialytic removal.