Small hard spots on the penis can be caused by warts, folliculitis, sclerodactyly, penile pearly papules and penile cancer. 1. Condyloma acuminatum: Condyloma acuminatum in the penis is mainly manifested as tiny reddish papules, which can be accompanied by cauliflower-like changes, and can gradually increase with the progress of the disease, which can show small hard spots. 2. Folliculitis: folliculitis can appear red isolated papules, small hard point-like changes, with the progress of the disease can appear papular pustules, need to timely medical treatment. 3. penile sclerosis: due to riding straddle injury, excessive masturbation, inflammatory stimulation and other factors, can cause penile corpus cavernosum fibrosis, local hard nodule-like manifestations. 4. Pearly papules: due to local stimulation and physiological developmental variations, it can cause pearly papules in the penis, which mostly occur in the coronal margin and coronal sulcus and other parts of the penis, and pearly and translucent papules can appear. 5. Penile cancer: in the early stage of penile cancer, local thickening of penile skin can occur, and scleroderma-like papules can appear, and erosion and hardening can occur after ulcerative changes. When there are small hard spots on penis, one should consult doctor in time and take appropriate treatment under the guidance of specialized doctors, which can help to cure the disease as early as possible.