Lifetime preweaning production traits are important for increasing profitability in commercial swine operations. Sows with larger preweaning production from the first to the last parity in her lifetime are preferred. Thus, it is important to determine how heritable lifetime pre-weaning production traits are in swine populations under tropical conditions in Thailand. Consequently, the objective of this study was to estimate genetic parameters for characteristics of lifetime pre-weaning production traits of Landrace (L) sows raised in an open-house system in Thailand. The pre-weaning production traits were number of piglet born alive (NBA), number of piglets weaned (NPW), average weight of piglets at birth (ABW), and average weight of piglets at weaning (AWW). The characteristics considered for these traits were first-parity value (FPV), peak-parity value (PPV), number of parities from first-parity to peak-parity (P1P), and persistency from the third to the last parity (regression coefficient; P3L). The data set contained 6,075 performance records from 941 sows that farrowed from 2004 to 2012. Variance components for each characteristic were estimated separately for the 4 traits using an AI-REML procedure. The 4-trait animal model for each characteristic included first-farrowing year-season and age at first farrowing as fixed effects, and sow and residual as random effects. Heritability estimates ranged from 0.04 (NPW) to 0.10 (ABW) for FPV, 0.06 (NPW) to 0.20 (NBA) for PPV, 0.01 (NBA) to 0.04 (ABW) for P1P, and 0.03 (NPW) to 0.17 (ABW) for P3L. Genetic correlation estimates ranged from −0.47 (NPW-AWW) to 0.87 (ABW-AWW) for FPV, −0.10 (NPW-AWW) to 0.85 (ABW-AWW) for PPV, −0.73 (NBA-NPW) to 0.58 (NBA-AWW) for P1P, and −0.70 (NPW-AWW) to 0.13 (NPW-ABW). The low estimates of heritability for all characteristics in these 4 lifetime preweaning production traits indicated that genetic improvement for these characteristics in all these traits would either be slow or nonexistent in this Landrace population.