Axial spondyloarthritis (axSpA) is an inflammatory rheumatic disease, which belongs to the group of spondyloarthritis, and predominantly affects the axial skeleton. Research shows that sulfasalazine (SSZ) can cause changes in the semen analysis (spermiogram). The patient, born in 1984, was referred to a rheumatologist due to back pain that had lasted for three years. During the clinical examination, there was pain in the left sacroiliac joint (SIJ ) as well as sternocostal entheses and restricted movements in the right hip. Further diagnostic processing determined the presence of the Human Leukocyte Antigen (HLA ) B27. Magnetic resonance imaging confirmed the existence of chronic changes in the left SIJ , degenerative changes in the right hip with areas of bone marrow edema, a smaller amount of effusion and synovial thickening. A diagnosis of non-radiographic axSpA was made. SSZ was introduced along with non-steroidal anti-rheumatic drug (NSAID) therapy. Five months after sulfasalazine (SSZ) was introduced into therapy, drug-induced infertility was suspected. A spermiogram was performed, and, following that, oligoasthenozoospermia was confirmed: reduced absolute sperm count (9.95 — reference interval (ref.int.) > 39 million/ milliliter [ml]), reduced sperm concentration (2.94 — ref. int. > 15 million/ml), reduced sperm motility percentage (17 — ref. int. > 40%), reduced percentage of progressively motile sperm (17 — ref. int. > 32%) and immotile sperm result: 83/ml. SSZ was discontinued, which resulted in an improvement in all of the semen parameter findings. The causes of infertility in men are multifactorial, they are related to the underlying disease, drug therapy and other urological, endocrinological and genetic causes. Most studies on the effects of sulfasalazine (SSZ) on fertility were conducted on patients suffering from inflammatory bowel diseases. The mechanism of toxicity of sulfasalazine (SSZ) on infertility is unknown. The assumption is that the active metabolite, sulfapyridine, leads to oxidative stress with consequent effects on semen quality. Routine monitoring of sexual function and family planning is necessary.