Desalted Salicornia europaea L. (SE) inhibits acetylcholine esterase, attenuates oxidative stress and inflammatory cytokines, and activates neurotrophic pathway. We performed 12-week, randomized, double-blind, placebo-controlled study to evaluate the efficacy of PhytoMeal(a desalted SE)-ethanol extract (PM-EE), in improving the cognitive performance in patients with subjective memory impairment. 63 participants complaining memory dysfunction without dementia (Korean Mini-Mental State Examination [K-MMSE] score ≥ 23) were assigned to PM-EE 600 mg/day or placebo. The cognitive domain of the Alzheimer's disease assessment scale-Korean version (ADAS-K) was set as the primary outcome. After 12 weeks, there was no differences in the changes in the primary outcome or the frequency of adverse events between the groups. In the subgroup analysis for the 30 subjects with mild cognitive impairment (MCI, baseline K-MMSE scores ≤ 28), PM-EE significantly improved the color-reading score of the Korean color-word stroop test (8.2 ± 25.0 vs. - 4.7 ± 13.2, P = 0.018). Our findings suggest that PM-EE is safe but might not be effective in this setting of this study. However, PM-EE may improve the frontal executive function in the patients with MCI. Further large-sized studies with longer follow-up period is warranted (trial registration number KCT0003418).