This trial is conducted in Europe. The aim of this trial is to investigate the efficacy and safety of biphasic insulin aspart (NovoMix®30) to that of biphasic human insulin (Mixtard® 30) in subjects with type 2 diabetes.

Inclusion Criteria:

• Type 2 diabetes for at least 24 months
• Insulin treatment for the pase 3 months
• HbA1c (glycosylated haemoglobin) below 13%
• BMI (Body Mass Index) below 40 kg/m^2
• Ability and willingness to perform self-blood glucose monitoring

Exclusion Criteria:

• Receipt of any investigational drug within 4 weeks prior to this trial
• Treatment of OHAs (Oral Hypoglycaemic Agents) within 4 weeks prior to this trial
• Total daily insulin dosage less than or equal to 1.8 IU/kg