diff --git a/graphicsItems/ArrowItem.py b/graphicsItems/ArrowItem.py
index 22d0065b..0c6c0718 100644
--- a/graphicsItems/ArrowItem.py
+++ b/graphicsItems/ArrowItem.py
@@ -12,6 +12,10 @@ class ArrowItem(QtGui.QGraphicsPathItem):
     
     
     def __init__(self, **opts):
+        """
+        Arrows can be initialized with any keyword arguments accepted by 
+        the setStyle() method.
+        """
         QtGui.QGraphicsPathItem.__init__(self, opts.get('parent', None))
         if 'size' in opts:
             opts['headLen'] = opts['size']
@@ -40,6 +44,32 @@ class ArrowItem(QtGui.QGraphicsPathItem):
         self.moveBy(*self.opts['pos'])
     
     def setStyle(self, **opts):
+        """
+        Changes the appearance of the arrow.
+        All arguments are optional:
+        
+        ================= =================================================
+        Keyword Arguments
+        angle             Orientation of the arrow in degrees. Default is
+                          0; arrow pointing to the left.
+        headLen           Length of the arrow head, from tip to base.
+                          default=20
+        headWidth         Width of the arrow head at its base.
+        tipAngle          Angle of the tip of the arrow in degrees. Smaller
+                          values make a 'sharper' arrow. If tipAngle is 
+                          specified, ot overrides headWidth. default=25
+        baseAngle         Angle of the base of the arrow head. Default is
+                          0, which means that the base of the arrow head
+                          is perpendicular to the arrow shaft.
+        tailLen           Length of the arrow tail, measured from the base
+                          of the arrow head to the tip of the tail. If
+                          this value is None, no tail will be drawn.
+                          default=None
+        tailWidth         Width of the tail. default=3
+        pen               The pen used to draw the outline of the arrow.
+        brush             The brush used to fill the arrow.
+        ================= =================================================
+        """
         self.opts = opts
         
         opt = dict([(k,self.opts[k]) for k in ['headLen', 'tipAngle', 'baseAngle', 'tailLen', 'tailWidth']])