Background/Aim. The bladder outlet obstruction (BOO) index (BOOI) is used during urodynamic testing to diagnose BOO. The bladder contractility index (BCI) is a urodynamic parameter used inconsistently. The aim of this study was to examine the correlation between BOOI and BCI. Methods. A retrospective study was conducted from 2021 to 2023, including 176 male patients. Using the t-test, analysis of variance, and correlation analysis, BOOI and BCI were analyzed. Results. High BOOI values (40–80) and weaker bladder contractility (BCI < 100), as potential causes of lower urinary tract symptoms (LUTS), coexisted in 11.37% of cases. A high BCI value (> 150) was associated with a significant number of patients (7.39%) with high BOOI values (> 40), acting as a compensatory mechanism that masked the true causes of LUTS. Patient groups with BCI < 100 and > 150 showed an inverse correlation with BOOI, as expected. Values of BOOI 20–39 and BCI 101–149 were considered a “gray zone”. The correlation between P_detQ_max and Q_max was not statistically significant (r = -0.2006), making BOO a factor that could influence this relationship. Additionally, the intraurethral catheter positioned during urodynamic testing significantly affected this correlation. As expected, a negative correlation was observed between Q_max and BOOI (r = -0.44841, p < 0.001), while BCI and Q_max had a positive linear correlation (R² = 0.2255, p < 0.001). The correlation between the two observed indices, BOOI and BCI, showed a positive linear correlation, presenting a physiological mechanism for BOO compensation (R² = 0.3292, p < 0.001). Conclusion. In combination with BCI, BOOI is sufficient for establishing a definitive diagnosis in the analyzed patient groups. It is recommended that BOOI, BCI, and Q_max always be used in combination. Q_max, as a measure mostly valued on uroflow, may be insufficient for diagnosis in unequivocal clinical cases.