One more way...

vb Code:
  1. Dim PDFFilPth As String
  2. PDFFilPth = "C:\Temp\"
  3.  
  4. 'When it finds a PDF file, it adds it to a Combox (cmbPDF):
  5. ' Find PDF in Multiple Folders and Lists them
  6. Dim rootDi As New DirectoryInfo(PDFFilPth)
  7. Dim di As DirectoryInfo
  8. For Each di In rootDi.GetDirectories
  9.     Dim PDFdirs() As String = Directory.GetFiles(PDFFilPth & di.Name)
  10.     For Each PDFfilname In PDFdirs
  11.         PDFtestname = System.IO.Path.GetFileName(PDFfilname)
  12.         'Check for PDF files and add to Combox 'cmbPDF'
  13.         Dim FilTest As String = PDFtestname.Remove(0, (Len(PDFtestname) - 3))
  14.         If UCase(FilTest) = "PDF" Then
  15.             cmbPDF.Items.Add (PDFtestname)
  16.         End If
  17.     Next
  18. Next