Adequate forage chop length (CL) along with a sufficient dietary fiber content can benefit the rumen environment and cow performance. Numerous studies have investigated the CL of alfalfa and corn silage (CS), but there is less research on ryegrass silage (GS). Our aim was to evaluate the effects of GS CL and GS:CS ratio on the eating behavior and sorting activity of dairy cows. Grass silage was chopped at harvest at 2 mean CL (short or long) and either fed alone or mixed with CS at a GS:CS ratio of 40:60 (DM basis). All diets were supplemented with concentrates at a 54:46 (DM basis) and fed as a total mixed ration. Sixteen multiparous Holstein-Friesian cows were used in a 4 × 4 Latin square design with 4 periods of 28-d duration in a 2 × 2 factorial arrangement. Jaw activity was visually recorded through instantaneous scan sampling at 5-min intervals for 48h. Diet particle distribution was measured at 0 and 24h post-feeding for 5-d using a modified Penn State Particle Separator. Sorting was calculated as the actual intake of each fraction expressed as a % of the predicted intake of each fraction. Values < 100% indicate selective refusals, > 100% is preferential consumption, and = 100% is no sorting. Data were analyzed using a mixed model procedure. Cows when fed GS alone spent 1.1 h/d longer (P < 0.01) eating compared with those fed the GS:CS mix. Eating time was 2.84 min/kg DMI higher for the longer CL GS compared with the short CL. There was an interaction (P < 0.03) for ruminating time (RT) and RT (min/kg DMI), where a longer CL increased RT when fed the GS:CS mix but had little effect when fed GS alone. An interaction (P < 0.01) was also observed for sorting of > 19 mm fraction, where a shorter CL resulted in a refusals when fed GS alone but there was no sorting when fed the GS:CS mix. In contrast, cows when fed GS alone had a greater preferential consumption (P < 0.03) for the 4–8 mm fraction. In conclusion, a longer GS CL increased eating time but had no effect on ruminating time. Cows when fed GS as the sole forage source spent a longer time eating and ruminating that might benefit rumen function, but also resulted in more diet sorting.