© 2015 Lutz et al. Background: Pulmonary function decline is a major contributor to morbidity and mortality among smokers. Post bronchodilator FEV 1 and FEV 1 /FVC ratio are considered the standard assessment of airflow obstruction. We performed a genome-wide association study (GWAS) in 9919 current and former smokers in the COPDGene study (6659 non-Hispanic Whites [NHW] and 3260 African Americans [AA]) to identify associations with spirometric measures (post-bronchodilator FEV 1 and FEV 1 /FVC). We also conducted meta-analysis of FEV 1 and FEV 1 /FVC GWAS in the COPDGene, ECLIPSE, and GenKOLS cohorts (total n=13,532). Results: Among NHW in the COPDGene cohort, both measures of pulmonary function were significantly associated with SNPs at the 15q25 locus [containing CHRNA3/5, AGPHD1, IREB2, CHRNB4] (lowest p-value=2.17×10 -11 ), and FEV 1 /FVC was associated with a genomic region on chromosome 4 [upstream of HHIP] (lowest p-value=5.94×10 -10 ); both regions have been previously associated with COPD. For the meta-analysis, in addition to confirming associations to the regions near CHRNA3/5 and HHIP, genome-wide significant associations were identified for FEV 1 on chromosome 1 [TGFB2] (p-value=8.99×10 -9 ), 9 [DBH] (p-value=9.69×10 -9 ) and 19 [CYP2A6/7] (p-value=3.49×10 -8 ) and for FEV 1 /FVC on chromosome 1 [TGFB2] (p-value=8.99×10 -9 ), 4 [FAM13A] (p-value=3.88×10 -12 ), 11 [MMP3/12] (p-value=3.29×10 -10 ) and 14 [RIN3] (p-value=5.64×10 -9 ). Conclusions: In a large genome-wide association study of lung function in smokers, we found genome-wide significant associations at several previously described loci with lung function or COPD. We additionally identified a novel genome-wide significant locus with FEV 1 on chromosome 9 [DBH] in a meta-analysis of three study populations.