Introduction There is a dearth of studies to quantify the use of illicit fillers by transwomen. Case studies of illicit filler injections have pointed to an array of serious health complications, including death.

Aims The aims of this study were to determine the population prevalence and identify correlates of filler use among transwomen in San Francisco, CA.

Methods An analysis of data collected in 2013 with a population‐based sample of 233 transwomen recruited using respondent‐driven sampling (RDS). We used RDS weights to conduct bivariate and multivariate analyses of correlates of filler use.

Main Outcome Measures Main outcome measures were an RDS‐weighted population prevalence of filler use among transwomen and differences in demographic characteristics, transition‐related care factors, and self‐esteem related to appearance.

Results Weighted filler prevalence among transwomen was 16.7%. Being a transwoman between 30 and 49 years of age, owning/renting or living with a partner/family/friend, having had and planning to have surgery in the future, and having used nonprescribed hormones were all significantly associated with filler use. HIV was not associated with filler use.