Litter decomposition is a key component of the global carbon cycle, and a process of great importance for the function of forest ecosystems. The rate of litter decomposition shows significant variation both between different forest types and within forests of different successional stage. Considering that global change is expected to shift (directly) the abiotic conditions experienced by trees in a stand as well as (indirectly) the structure of stands, a sound understanding of how litter decomposition varies within forests of the same dominant species and environmental conditions but of different structure is important. To explore this question, we applied the litterbag method within the permanent forest plot monitoring network established on the island of Lesvos. We selected four Pinus brutia dominated plots under similar environmental conditions, across a fire chronosequence ranging from 15 to 90 years. Twenty-four litterbags were buried in each plot and sequentially removed after specific time periods. The percentage of the initial remaining mass was used as a response variable and modeled with a negative exponential and an asymptotic curve. Our findings show that the rate of litter decomposition increases with time since fire and standing biomass of the plot, highlighting the importance of maintaining mature forests in Mediterranean ecoregions.