The effect of coalescence and aggregation processes on the memristive properties of silver nanoparticle assemblies has been investigated. Nanoparticles were prepared by vacuum-thermal evaporation on silicon substrates with gold electrodes and quartz glasses for morphological control. The structure of the samples and size distribution of nanoparticles were studied using scanning electron microscopy (SEM) and UV-visible spectroscopy. Memristive properties were estimated using cyclic voltammetry. Due to Ostwald ripening and an increase in average nanoparticle size, the operating voltage required to switch the system into the memristive state decreased, while the conductivity dynamics changed. These findings are useful for ensuring the stability of memristive devices based on silver nanoparticle assemblies.