We report the presence of Chikungunya (CHIKV) RNA in the blood, urine and semen during the acute phase of the disease in an adult with a dual infection with Dengue virus type 3. The patient, a 25 yr-old man from Salvador, Brazil, reported a 6-day duration of high fever, arthralgia, myalgia, headache and photophobia.Blood and semen specimens were positive for CHIKV in the first collected samples; semen and urine specimens were positive for CHIKV after 30 days of symptoms onset. DENV-3 RNA was positive in blood specimen when first collected 6 days after the initiation of symptoms.We describe for the first time the presence of CHIKV RNA in urine and semen for an extended period of time and we address the possible implications of these findings for diagnosis and transmission dynamics.