<p>A study of <i>Octopus vulgaris</i> stock dynamics in the Moroccan Mediterranean (between Fnideq and Jebha) was carried out, based on size frequency data of a sample of 14,919 specimens derived from fishing trawlers and artisanal boats over a five-year period (2015–2019) using FISAT II software. Overall, annual fishing mortality (F) ranged from 4.47 to 5.81, with values between 3.01 and 4.83 for artisanal boats and between 6.92 and 10.64 for trawlers. Natural mortality M was 1.73/year for F = 4.96/year (Rikhter and Efanov) and 1.57/year (Pauly) for F = 5.12/year. The L_25%, L_50%, and L_75% estimated by the selectivity and cumulative frequency curves were similar for the trawlers. Recruitment was continuous throughout the year, with high peaks in March-April and lower peaks in September-October. Virtual population analysis showed that F, intense for the 6–10&#xa0;cm juvenile classes, explains the high overall exploitation rate (E = 0.76). Annual biomass (B) varied from 1760 tonnes in 2018 to 2921 tonnes in 2019. The annual spawning stock biomass (SSB) rate ranged from 5.8 to 8.4% during 2015–2018 increasing to 11.4% in 2019. No significant differences in annual F and B by size class for the different terminal F used were noticed. According to both Y’/R and Y/R predictive models, F_current was estimated at almost double for artisanal boats and five times for trawlers compared with F_msy. In the absence of a comprehensive model that fully incorporates all the specific ecological and biological characteristics of the Moroccan Mediterranean common octopus, this study offers a practical and cost-effective alternative for a stock assessment.</p>