The present invention concerns nucleated propylene polymers having a xylene soluble fraction at 23 °C of less than 2.5 %, a crystallization temperature of over 124 °C and a tensile modulus of greater than 2,000 MPa. These polymers can be prepared by nucleating a propylene polymer with a polymeric nucleating agent containing vinyl compound units, and by polymerizing propylene optionally with comonomers in the presence of a Ziegler-Natta catalyst system primarily transesterified with a phthalic acid ester - a lower alcohol pair to provide said propylene polymer. The catalyst contains a strongly coordinating external donor.