The aims of this reliability generalization study were to provide the overall alpha values of the California critical thinking disposition inventory (CCTDI) total score and subscales scores and investigate the characteristics of the studies that may be associated with the variability in the reliability values of the CCTDI total score and subscales scores. This study was carried out with 98 alpha values from 87 unique studies for total CCTDI scores. In the random effects model, total CCTDI was found to be reliable across samples with alpha value of 0.83. Also, the general alpha coefficients were 0.65, 0.56, 0.64, 0.66, 0.74, 0.72, and 0.61 for TS-scale, OM-scale, A-scale, S-scale, SC-scale, I-scale, and M-scale, respectively. Examination of study characteristics indicated that sample type was a significant predictor for alpha value of total CCTDI and all subscales. Samples with university students reported larger Cronbach's alpha estimates for total CCTDI and all subscales. Also, while language was found to moderate the general alpha coefficient of total CCTDI, OM-scale, A-scale, S-scale, and I-scale, it was not a significant moderator on the general alpha value of TS-scale, SC-scale, and M-scale. Total CCTDI and all subscales showed higher Cronbach's alpha values for the English-language administrations. Besides, country of the study was a significant moderator on the general alpha coefficient of total CCTDI, S-scale, and I-scale. However, subgroup of discipline was not a significant moderator on the general alpha coefficient of total CCTDI and its subscales. The mean of the test scores significantly explained %5 of the variance of alpha values of the total CCTDI. SD of the test scores significantly explained %10, %55, and %54 of the variance of alpha values of the total CCTDI, A-scale, and S-scale, respectively. It was found that gender and ethnicity significantly moderated the alpha values for M-scale.