The present study focuses on the chemical and morphological characterization of PM10 (particulate matter ≤10 µm) in the Aburrá Valley surrounding the city of Medellin, Colombia, a significant location due to its geography and urbanization. Using scanning electron microscopy (SEM) with energy dispersive spectroscopy (EDS), PM10 samples were analyzed. This revealed a variety of particles that include iron and other metal oxides, calcium sulfates, fly ash, magnesium-rich particles, soot, aluminosilicates, carbonates, phosphates, mixed aluminosilicate-sulfate-carbonate particles, mixed aluminosilicate-carbonate particles, and biological matter. This research shows the specific physic-chemical characterization of PM for a large, and urbanized valley, which in some periods of the years has a complex air flow that traps gases that increases pollution in the city, enabling the formulation and planning of more effective policies for Colombia, but that can be extended to many countries with similar environmental issues.