Background: Adiponectin, which may have a growth-promoting effect through its insulin-sensitizing action, is thought to play a key role in fetal growth. This study was performed to determine whether maternal and/or cord blood adiponectin concentrations differ between small for gestational age (SGA) and healthy controls. Methods: Databases were searched to identify good quality English language studies providing the number of SGA and healthy controls, and the means and standard deviations of maternal or cord blood adiponectin concentration in both groups. A meta-analysis was performed to summarize the standardized mean differences (SMDs) in maternal and cord blood adiponectin concentrations between SGA and healthy controls. Results: There was no statistically significant difference in maternal blood adiponectin concentration between SGA and healthy controls (n = 8, p = 0.951). However, cord blood adiponectin concentration was significantly lower in SGA than in healthy controls (n = 6, p = 0.028), and the effect was large (i.e., SMD >0.7). Conclusions: Maternal blood adiponectin concentration is not low in SGA compared with healthy controls. However, SGA shows lower cord blood adiponectin concentration than healthy controls.