Shah Jahah Khan, 62, and Muslim convert Ibrahim Anderson, 38, both from Luton in Bedfordshire, each deny one charge of inviting support for a banned organisation.
Westminster magistrates court heard that the charge relates to an offence on 9 August last year, when the pair are alleged to have handed out leaflets about Islamic State in Oxford Street.
Anderson also denied one charge of possessing information likely to be useful for the preparation of or carrying out an act of terrorism, when police searched his property in December last year.
Anderson and Khan remained standing throughout the hearing, “in accordance with their religious beliefs”, defence counsel Tony Lodge said.
Senior district judge Howard Riddle granted the two men conditional bail and they will appear at the Old Bailey on 15 May.