Psilocybe serbica has no specific smell (somewhat raddish, but never farinaceous), taste is usually bitterish. Its cap is (1)2–4(5) cm in diameter and obtusely conical, later becoming campanulate or convex. It expands to broadly convex or plane in age and is incurved at first then plane or decurved with age. The cap is buff-brown to dingy orangish-brown and pale ochraceous when dry. It is smooth, hygrophanous, and slightly translucent-striate when moist but not viscid and without a separable gelatinous pellicle. The flesh is whitish to cream-colored, bruising blue when injured. Spores are purple-brown, ellipsoid, slightly flattened, and thick-walled, with a distinct germ pore. The size is very variable, mostly 10–13 × 6–7.5 μm, but also much longer. The gills are adnate to adnexed and close, often distinctly subdecurrent. They are initially light brown, becoming dark brown with age with a purple tint, the edges remaining paler. The stipe is 4.5-8(10) cm by 2–10 mm. It has an equal structure, slightly enlarging at the base. It is whitish with a silky gloss and glabrous, or with some whitish remnants of the fibrillose veil. Psilocybe serbica is found growing mostly in groups, on well decayed deciduous and coniferous wood, and along urtica spp. or rubus spp. on twigs, compost, plant residue, in forests, usually in moist places along creeks, forest path and roadside verges. Not reported to be synanthropic.