It might be, but more likely it is because of the difference in speakers and room acoustics between your studio and your home.
Here is something very important you should try to make a habit of doing: always compare your mixes to familiar (commercial) reference recordings that are similar in sound and style. If the commercial reference recording sounds like shit, either at home or in the studio, then you know something is screwed up in your listening environment.
It's very common to mix a song with way too much low end, or way too little highs, or visa versa. When you check it against the reference, though, it will be come immediately apparent. (Hey! What happened to all the low end on this P-Funk record???) If the reference CD sounds bass lite, for instance, it means that your ears have adjusted to hearing way too much bass, and you better back it off in your mix.
Without the reference, your mixes don't have much chance of coming out "right", especially if there are problems with the room or speakers.