The salting effect, of kosmotropic and chaotropic salts, on nanoscale and giant-poly(ethylene oxide)16-block-poly(butylene oxide)22 polymersomes was studied. Nanovesicles were studied by dynamic light scattering and transmission electron microscopy and their aggregates (i.e., gel-like structures) by optical microscopy. Giant polymersomes were formed using drop-on-demand inkjet printing and subsequently observed using an optical microscope. The kosmotropic salts were found to strongly influence both vesicle aggregation and giant vesicle (above 3 μm) formation at high salt concentrations (i.e., ~0.5 M for nanovesicle aggregation and 0.23 M for giant polymersomes) where the salting effect dominates. Chaotropic salts have very little effect in both systems. The ionic specificity effect essentially determined the outcome of experiments since the type of anion provides different ion/water/ poly(ethylene oxide) interactions and different osmotic stress values, which can be considered the main driving forces and lead the effects observed in experiments (nanovesicle aggregate experiments and abundant giant vesicle formation experiments). The applications of the present work may be lead to better methodologies to produce gel scaffolds for biomaterials or giant unilamellar polymersomes.