To systematically review the diagnostic accuracy of spot urinary protein to creatinine ratio (PCR) and 12-h proteinuria in preeclampsia and to estimate which is a preferred alternative method for 24-h proteinuria, we carried out this meta-analysis. 25 primary studies were included based on searching strategy. For spot urinary PCR, our results showed pooled sensitivity of 87% (95% confidence interval [CI] 83%-91%) and specificity of 86% (95% CI 79%-91%), with an area under curve (AUC) of 0.93 (0.90-0.95). For 12-h proteinuria, pooled sensitivity and specificity were 92% (95% CI 87%-96%) and 99% (95% CI 75%-100%), respectively, with an AUC of 0.97 (0.95-0.98). Fagan plot and likelihood ratio scattergram showed that 12-h proteinuria yielded a better discriminatory performance on diagnosis of proteinuria (≥0.3 g/24 h). These results indicated that 12-h proteinuria estimation shows better clinical value than spot urine PCR for diagnosis of preeclampsia. However, due to the severity of condition and the fact that preeclampsia patients cannot wait for 12 h, spot urine PCR can be used as one of the diagnostic indicators.© 2024 The Author(s).