In this paper, we consider the two equations p 3 + q 3 = z 2 and p 3-q 3 = z 2 when p, q are primes. Among the various results attained, it is shown that both equations have no solutions when q = 2, and z 2 is a multiple of 9 in each and every solution. In particular, when 3 ≤ q < p ≤ 101, all the possibilities for solutions of each equation are examined for all primes p, q. It is established that each equation has exactly one solution which is exhibited. For primes larger than 101, it is presumed that both equations may have additional solutions by using a computer.