Subjective olfactory decline (SOD), does not correlate well with olfactory performance and is sometimes regarded as an unreliable assessment, yet it is associated with future risk of dementia. Here, we compared SOD with subjective cognitive decline (SCD), which is known to be associated with an increased risk for future cognitive impairment and dementia. We aimed to test whether SOD and SCD are associated with olfactory and/or cognitive performance at 10 years follow-up. We used data from a population-based sample aged 45 to 90 years at baseline (n=307; 52% female). The sample was split into healthy controls (HC), SOD and SCD. General cognitive status (Mini-Mental State Examination) and olfaction (Scandinavian Odor Identification test; SOIT) were assessed in all subjects. We used within-subjects ANOVA for baseline-to-follow-up comparisons and multiple linear regression models for each group at follow-up to test for the association between objective olfaction and cognition measured with several cognitive test. Individuals with SOD had no olfactory impairment at baseline, but an impairment emerged at follow-up. In this group, SOIT scores at follow-up were positively associated with their cognitive scores. There were no significant associations between cognition and olfaction in the SCD group. Subjective olfactory complaints may indicate subtle olfactory deficits that may later become observable and may also indicate future cognitive status. The research was supported by the Swedish Research Council (2020:00266) to J.K.O.