  We discuss the technique of Wide-field imaging as it applies to Very Long
Baseline Interferometry (VLBI). In the past VLBI data sets were usually
averaged so severely that the field-of-view was typically restricted to regions
extending a few hundred milliarcseconds from the phase centre of the field.
Recent advances in data analysis techniques, together with increasing data
storage capabilities, and enhanced computer processing power, now permit VLBI
images to be made whose angular size represents a significant fraction of an
individual antenna's primary beam. This technique has recently been
successfully applied to several large separation gravitational lens systems,
compact Supernova Remnants in the starburst galaxy M82, and two faint radio
sources located within the same VLA FIRST field. It seems likely that other
VLBI observing programmes might benefit from this wide-field approach to VLBI
data analysis. With the raw sensitivity of global VLBI set to improve by a
factor 4-5 over the coming few years, the number of sources that can be
detected in a given field will rise considerably. In addition, a continued
progression in VLBI's ability to image relatively faint and extended low
brightness temperature features (such as hot-spots in large-scale astrophysical
jets) is also to be expected. As VLBI sensitivity approaches the $\mu$Jy level,
a wide-field approach to data analysis becomes inevitable.
