Dim MyProcess As New Process
MyProcess.StartInfo.CreateNoWindow = False
MyProcess.StartInfo.Verb = "print"
MyProcess.StartInfo.FileName = "C:\Test.pdf"
MyProcess.Start()
MyProcess.WaitForExit(10000)
MyProcess.CloseMainWindow()
MyProcess.Close()
Or
Dim PrintPDF As New ProcessStartInfo
PrintPDF.UseShellExecute = True
PrintPDF.Verb = "print"
PrintPDF.WindowStyle = ProcessWindowStyle.Hidden
PrintPDF.FileName = pdfFileName
Process.Start(PrintPDF)