PIP: This study examined patterns in the sex ratio at birth (SRB) in impoverished provinces and counties in China. Data were obtained from the 1990 census for 586 impoverished counties. SRB in the impoverished counties was 109.43 in 1989. SRB was calculated and ranked according to the difference between each province and its impoverished areas. The differences are under -5, and between -5 and -1, -1 and 0, 0 and 1, 1 and 3, and above 3. 10 provinces and autonomous regions (ARs) had few differences. 4 provinces and ARs had lower provincial SRB than in impoverished areas: Tibet, Hebei, Sichuan, and Inner Mongolia. The third group included 8 provinces where SRBs were much higher than in impoverished areas and higher than the national average. The fourth group included very high SRBs in the provinces and ARs (Fujian, Guangxi, and Guangdong). Mapping of the counties with high SRBs indicated contiguity. The fifth group was Liaoning province where SRB was 110.10; SRB was 117.8 in impoverished areas and the highest in the nation. 10 out of 1735 counties with the highest SRBs included 5 in Zhejiang province and clustered in Wenzhou prefecture; 2 were in Hebei; and 1 each was in Shandong, Jiangsu, and Guangxi. In 15 impoverished counties among 78 counties with high SRB, 13 were clustered in 3 major regions. SRB was related to both higher and lower levels of economic development. Higher SRB in counties was related to the implementation of the family planning policy. The 3 counties with the lowest SRB were impoverished. 26 counties with the lowest SRB included 11 impoverished counties.