  Broad Absorption Line Quasars (BAL QSOs) have been found to be associated
with extremely compact radio sources. These reduced dimensions can be either
due to projection effects or these objects might actually be intrinsically
small. Exploring these two hypotheses is important to understand the nature and
origin of the BAL phenomenon because orientation effects are an important
discriminant between the different models proposed to explain this phenomenon.
In this work we present VLBA observations of 5 BAL QSOs and discuss their
pc-scale morphology.
