Understanding the anatomy of endocrine glands in fish allows for the formulation of a strategy for their reproduction. The current investigation aimed to investigate the immunohistochemical identification of hormonal-secreting cells in Mugil cephalus pituitary gland. Antisera against both piscine and mammalian hormones were used to complete the immunohistochemistry of the cell types in M. cephalus pituitary gland. The adenohypophysis and the neurohypophysis made up the two main sections of M. cephalus's hypophysis. Moreover, the adenohypophysis obtained exhibited three subdivisions: rostral pars distalis (RPD), proximal pars distalis (PPD), and pars intermedia (PI). In the glandular portion, seven cell types were identified according to their distribution, immunoreactivity, and grouping. The cells of prolactin (PRL) were acidophilic and occupied most of the RPD. They responded positively and specifically to antiserum against salmon PRL. Positive immunoreactivity was observed by antiserum of human adrenocorticotrophic (ACTH), within the lead hematoxylin-positive (PbH+) cells that surrounded the RPD neurohypophysis. Salmon growth hormone (GH) antiserum produced a specific and intense immunoreactivity in the PPD's acidophilic cells. Furthermore, basophilic cells, exhibiting a strong and distinct immunoreactivity to antisera against the subunits Iβ and IIβ of salmon gonadotropin (GTH), were localized in PPD's central area. The cells thought to secrete thyrotropin (TSH) were located between the PPD and RPD in the neurohypophysis. They underwent an adverse immunoreactivity when reacted to rat thyrotropin (rBetaTSH) antiserum. Within the PI, two cell types were identified: PbH+ cells that immunoreacted with alpha-melanin-stimulating hormone (α-MSH) antiserum and cells that displayed a positive immunoreaction to anti-salmon somatolactin (SL) and were classified as Periodic Acid-Schiff-positive (PAS+). Current pituitary gland immunohistochemistry of M. cephalus may help to explain hormonal alterations that take place during reproduction in the nature, in captivity, or when this fish is receiving hormonal treatments.