The automobile exhaust significantly reduced the branch length and yield of Guaiacum officinale, Azadirachta indica and Eucalyptus sp. The yield of Azadirachta indica, Eucalyptus sp. and Guaiacum officinale was lessened at the polluted sites of the city. The increase in branch length of all the species was found mainly in control as compared to polluted sites. The branch length and seed weight of G. officinale and Eucalyptus sp. reduced significantly (p<0.05) at highly polluted sites of the city i.e. M.A. Jinnah Road as compared to control. Eucalyptus sp. showed maximum branch length (2.36 cm) at campus (Control) as compared to Shaheed-c-Millat Road (2.04 cm) Liaquatabad (1.97 cm) and M.A.Jinnah Road (1.82 cm), respectively in the month of July. However the lowest increase in branch length of Eucalyptus sp. (1.7 cm) was found at the highly polluted site on the forth week of observation in the month of June at M.A. Jinnah Road followed by Shaheed-c-Millat Road (2.0 cm) Liaquatabad (2.03 cm) and Campus (2.24 cm), respectively. Azadirachta indica showed maximum reduction in branch length at M.A. Jinnah Road (0.94 cm) followed by Shaheed-e-Millat Road (1.18 cm), Liaquatabad (1.30 cm) and Campus (2.02 cm) on the forth week of observation in June. Guaiacum officinale showed the minimum branch length at M. A. Jinnah Road (1.94 m) on eight weeks of observation in the month of July.