Despite its diversity pledges, Twitter employs just 49 black people out of its total US workforce of 2,910.
The tiny number of African American staff - 35 men and 14 women - represents just 1.7 percent of Twitter's US staff, The Guardian reported.
Twitter's Equal Employment Opportunity (EEO) report, a legally mandated filing with the US Equal Employment Opportunity Commission, showed that 93.8 percent of employees were white or Asian, with just 180 people out of a total workforce of 2,910 being drawn from other minorities.
Twitter's lack of minority employees contrasts starkly with the rainbow nature of its users. Data from the Pew Research Centre shows that 27 percent of black adults and 25 percent of Hispanics use Twitter, compared to just 21 percent of white people.
The company has repeatedly made pledges to make its staff more diverse, something that can better reflect the diversity of its 302 million users.
African Americans account for 13.6 percent of the US population, according to the 2010 US census.
Announcing a plan to "build a Twitter we can be proud of" last year, Twitter's vice-president of diversity and inclusion, Janet Van Huysse, said: "We are committed to making inclusiveness a cornerstone of our culture."
Gender and racial diversity is weak across Silicon Valley tech firms, with Facebook found to have hired an additional seven black people (including just one black woman) out of an overall headcount increase of 1,231 in 2013.
