Multi-criteria approaches are needed to integrate the agronomic, environmental, and socio-economic performances of intercropping agroecosystems and asses their sustainability. Nonetheless, the temporal dynamics of intercropping agrosystems still need to be better understood, particularly in tropical systems. This study provides the first long-term multi-criteria analysis of sugarcane intercropping systems to assess how temporal changes will determine the sustainability of this practice. In an experimental trial in La Reunion, we compared six sugarcane x companion crop intercropping systems to a conventional and a low weed control cropping system over seven years. In intercropping systems, weed cover increased over time, along with species richness and manual weeding. In the conventional system, herbicide application increased over time, reducing weed pressure. Regarding biodiversity, the intercropping system only modified the weed community in the first three years, compared with the conventional or low-weed control system, before the communities homogenized under sugarcane pressure and climate. Over seven years, the intercropping system reduced herbicide application by 51% and increased soil cover by 144%, with no significant impact on yield or sucrose content. Nevertheless, this practice led to an increase of 85% in costs and 162% in working hours, mainly due to companion crop sowing. Finally, we observed no difference in soil chemical and biological fertility between cropping systems. However, the physical fertility increased with the development of companion crops and weeds in the inter-row after seven years. This study illustrates the need to consider the dynamics of intercropping systems performances over the long term. It highlights the limits of this system for weed control in sugarcane, notably through an increase in weed pressure over time, but also ways of improving it regarding costs (particularly sowing). Finally, cropping systems with spontaneous flora in the inter-row should be studied further to reduce herbicides with a limited impact on production.