The Universe is not only visible through radio, optical or X-ray “eyes”, but also through gamma-ray “eyes”. In fact, the gamma-ray spectral range alone covers more decades in energy or frequency compared to the eleven decades in energy covered between radio waves and hard X-rays alone. The ideal course in High Energy Astrophysics and Pulsars should rely on the knowledge built up during the Honors courses. However, for 2003, we will have to assume that the proper foundations are less ideal, in which case relevant material from some Honors courses will be duplicated. There are several ways to probe high-energy processes: through the direct measurement of high-energy particles, or cosmic rays, and the direct measurement of non-thermal emission in the radio, optical, X-rays up to the gamma-ray range (as shown in this picture of the broad-band spectrum of the Crab Nebula or Messier 1). In the case of pulsars, we find that this emission is associated with rapidly rotating neutron stars, which accelerate charged particles as a result of the dynamo processes. Particle acceleration occurs in our galaxy, as well as in extragalactic objects. This course will cover the fundamental principles of this process in a few types of cosmic sources. Those accelerated particles, which escape from a source, finally contribute to the bulk of cosmic rays in our galaxy, and some of these particles are detectable at earth. The second part of the course concentrates on neutron stars and pulsars: Emphasis is given in their properties, observable phenomena, their interior structure, as well as the magnetosphere with associated particle acceleration leading to pulsed gamma-ray emission.