pH‐responsive microgel particles with a diameter between 200 and 600 nm, comprising either basic or acidic moieties, have been synthesized by emulsion polymerization. Basic microgels were prepared by the polymerization of the hydrophobic monomer 2‐(diethylamino)ethyl methacrylate (DEAEMA), while t‐butyl methacrylate (t‐BuMA) was used as the protected ester monomer to obtain methacrylic acid (MAA)‐based microgel particles following acid hydrolysis of the ester groups. These microgels exhibit reversible swelling in water in response to changes in the solution pH. Thus, when ionized, the microgel particles are swollen due to the electrostatic repulsions between the charged monomer repeating units and the osmotic pressure created within the microgel particles by the presence of the counterions to the charged monomer units. The solution properties of the polymer microgels were investigated as a function of the solution pH by potentiometric titrations, and the effective ionization constant (Kα) of the microgels was determined. Dynamic light scattering was used to characterize the swelling behavior of the microgels as a function of the degree of ionization of the monomer residues. The tertiary amine‐based microgels swell at low pH upon protonation of the amine units, while the PMAA microgels are swollen at high pH when the acid groups become neutralized. A change of the solution pH above or below a critical value (the effective pKα of the protonated monomer repeating units) leads to the formation of collapsed PDEAEMA or PMAA latex particles, respectively. Transmission electron microscopy was used to confirm the shape and size of the microgel particles while their morphology was also characterized by scanning electron microscopy. These pH‐responsive microgels can be used as colloidal templates for the in‐situ synthesis of inorganic nanoparticles at high loadings and in controlled drug delivery.