Approximately 5-20% of postpartum women suffer from long-lasting pelvic girdle pain (PGP). The etiology and pathogenesis of PGP are still unclear. The aim of this study was to examine whether subjects with and without persisting PGP and disability differed with respect to their ability to voluntarily contract the deep abdominals (TrA and IO) and to the strength of the pelvic floor muscles (PFM). Twenty subjects (12 with persisting PGP, 8 recovered from PGP) were examined. Contractions of the deep abdominal muscles (TrA and IO) were imaged by real-time ultrasound. Vaginal palpation and observation were used to assess the women's ability to perform correct a PFM contraction. PFM strength was measured by a vaginal balloon catheter connected to a pressure transducer. The active straight leg raise test was used to assess the ability of load transfer. The results showed no statistical significant difference between the groups in increase of muscle thickness of the deep abdominal muscles (TrA; P = 0.87 and IO; P = 0.51) or regarding PFM strength (P = 0.94). The ability to voluntarily contract the deep abdominal muscles and the strength of the PFMs are apparently not associated to PGP. However, the results are based on a small sample and additional studies are needed.