We used two national surveys (2010: N=1,597; 2013: N=1,057) of people who inject drugs (PWID) in past-month to assess the prevalence and population size of PWID with either safe or unsafe injection and sex behaviors, overall and by HIV status. In 2013, only 27.0% (vs. 32.3% in 2010) had safe injection and sex, 24.6% (vs. 23.3% in 2010) had unsafe injection and sex, 26.4% (vs. 26.5% in 2010) had only unsafe injection, and 22.0% (vs. 18.0% in 2010) had unsafe sex only. Among HIV-positive PWID in 2013, only 22.1% (~2200 persons) had safe injection and sex, 14.2% (~1,400 persons) had unsafe injection and sex, 53.1% (~5200 persons) had unsafe injection, and 10.6% had unsafe sex (~1,100 persons). Among HIV-negative PWID in 2013, only 27.5% (~22,200 persons) had safe injection and sex, 25.9% (~20,900 PWID) had unsafe injection and sex, 23.2% (~18,700 persons) had unsafe injection, and 23.3% (~18,800 persons) had unsafe sex. HIV-positive and -negative PWID in Iran continue to be at risk of HIV acquisition or transmission which calls for targeted preventions services.