Background and Objectives: Individuals with cystinuria can experiment recurrent lithiasis events due to the relative insolubility of cystine at physiological urine pH, resulting in renal function decline. The Lit-Control® pH Meter is a medical device that accurately allows urine pH self-monitoring. The main objective of this study was to compare the usability of the Lit-Control® pH Meter with the reactive strips for self-monitoring of urinary pH at home by patients with cystinuria, and their overall satisfaction with each tool., Patients and Methods: We included 28 patients (9 females and 19 males, age 19-76 years), who were randomly assigned to monitor their urine pH with reactive strips (n = 17) or the Lit-Control® pH-meter (n = 11)., Results: After six months of use, the satisfaction with the two methods was similarly high, but the patients rated (0-10 scale) the pH meter better in terms of ease of learning (mean ± SD, 8.11 ± 0.60 vs. 7.06 ± 1.18; P = 0.038), ease to prepare (8.22 ± 0.67 vs. 7.25 ± 1.18; P = 0.034), and ease of use (8.22 ± 0.67 vs. 7.25 ± 1.39; P = 0.062). Overall, patients did not reach the alkalinization goals (pH between 7.0 and 8.0)., Conclusions: The Lit-Control® pH Meter demonstrated to be an easy-to-use device that can facilitate urinary pH control by cystinuric patients. A prospective study is warranted to assess the correlation between urine pH monitoring, a treat to target approach, and the recurrence of cystine stones., (Copyright © 2023 The Author(s). Published by Elsevier España, S.L.U. All rights reserved.)