In this paper, we study on the exponential Diophantine equations: n x + 24 y = z 2 , for n ≡ 5 or 7 (mod 8). We show that 5 x + 24 y = z 2 has a unique positive integral solution (2, 1, 7). Further, we show that for k ∈ N, (8k + 5) x + 24 y = z 2 has a unique solution (0, 1, 5) in non-negative integers. We also show that for a perfect square 8m, the exponential Diophantine equation (8m − 1) x + 24 y = z 2 , m ∈ N has exactly two non-negative integral solutions (0, 1, 5) and (1, 0, 8m). Otherwise, it has a unique solution (0, 1, 5). Finally, we illustrate our results with some examples and non-examples.