Conventional therapies for human papillomavirus infection aim to remove clinically apparent lesions, while latent infection may remain, representing a threat for transmission and carcinogenesis. The use of a systemic agent may more effectively control the virus. We conducted a randomised placebo-controlled study to investigate the efficacy and safety of oral inociplex in the treatment of cervical condylomata acuminata (CA) that had been resistant to conventional therapies. Thirty-eight white European women, aged 20–43 years, with genital warts of the cervix, refractory to at least one conventional therapy, were randomly assigned to receive either inosiplex, 50 mg/kg daily peros for 12 weeks (group 1), or placebo (group 2). Of the 17 evaluable group 1 women, 4 responded to the treatment completely, 7 responded partially and 6 did not respond. Of the 19 group 2 women, none responded to the treatment completely, 3 responded partially and 16 did not respond. The therapeutic difference between women receiving active and placebo therapy was statistically significant (χ2= 6.69, P < 0.01) and remained significant when an intention-to-treat analysis was performed (χ2= 7.69, P < 0.01). None of the complete responders experienced recurrence during the 12-month follow up. Adverse effects were mild and resolved upon completion of therapy. Compared with placebo, inosiplex showed considerable efficacy with insignificant and reversible adverse effects and without recurrences. Inosiplex may represent an efficacious and safe alternative systemic form of therapy for cervical genital warts.