Approximately 1 μs after the Big Bang, the Universe was in the state of a Quark- Gluon Plasma (QGP), an ultra hot and dense state of matter, consisting of quarks and gluons. With the Large Hadron Collider (LHC) at CERN, in Switzerland, the properties of the QGP are studied by recreating this state of matter in collisions between lead ions. Studies of collisions between protons and lead ions have shown that smaller systems can also possess features of collectivity reminiscent of a QGP. This is a surprising and interesting discovery since it was thought until recently that only large overlap volumes, reached in collisions between nuclei, could present such a feature. The charged-particle multiplicity is one of the most fundamental measurements in heavy-ion physics. It provides insights into the mechanisms of particle production, and it is sensitive to the number of collisions between quarks and gluons. In this work, the charged-particle multiplicity distribution in p-Pb collisions at 5.02 TeV over a wide kinematic range (−3.4 < η < 5.1) is measured and presented, using LHC data from run 2, taken in 2016. The data were obtained using the Forward Multi- plicity Detector (FMD) and the Silicon Pixel Detector (SPD) of ALICE (A Large Ion Collider Experiment) at the LHC. Differential results are also obtained by dividing the multiplicity distributions into centrality classes (classes that are proportional to the number of interactions the proton undergoes as it collides with the lead-ion), using the V0A and ZNA centrality estimators.