A passive air sampling network has been established to investigate polychlorinated dibenzo-p-dioxins (PCDD) and polychlorinated dibenzofurans (PCDF) at Global Atmospheric Passive Sampling (GAPS) sites and six additional sites in the Group of Latin American and Caribbean Countries (GRULAC) region. The air sampling network covers background, agricultural, rural and urban sites. Samples have been collected over four consecutive periods of 6 months, which started in January 2011 (period 1 (January 2011 - June 2011), period 2 (July 2011 - December 2011), period 3 (January 2012 - June 2012) and period 4 (July 2012 - January 2013)). Results show that: i) the GAPS passive samplers (PUF disk type) and analytical methodology are adequate for measuring PCDD/F burdens in air, and ii) PCDD/F concentrations in air across the GRULAC region are widely variable by almost two orders of magnitude. The highest concentrations in air of Σ4-8PCDD/Fs was found at the urban site São Luis (Brazil, UR) (i.e. 2560 fg/m3) followed by the sites in São Paulo (Brazil, UR), Mendoza (Argentina, RU) and Sonora (Mexico, AG) with 1690 fg/m3, 1660 fg/m3 and 1610 fg/m3, respectively. Very low concentrations of PCDD/Fs in air were observed at the background site Tapanti (Costa Rica, BA) with 10.8 fg/m3. This variability is attributed to differences in site characteristics and potential local/regional sources as well as meteorological influences. The measurements of PCDD/Fs in air agree well with model predicted concentrations performed using the Global EMEP Multi-media Modeling System (GLEMOS) and emission scenario constructed on the basis of the UNEP Stockholm Convention inventory of dioxins and furans emissions.