Is it a defined benefit scheme (final salary or average salary scheme) or a defined contribution money purchase scheme you pay a set amount and your benefit depends on how well the fund performs).
If employe contributes too then it's usualy worth having. Also you get tax relief on contributions- this is especially worthwhile if you are a higher rate taxpayer.
But small value schemes may not be worthwhile as what you get from your eventual pension may be offset by a reduction in your state benefits (pension credit).
Can you give us more info on your scheme?