I will be going BA to Mar del plata on Feb. 7 and return to BA on Feb. 11.
I looked in some travel books for info about the trains between the above
and found nothing.
Does somebody have any info ? ( Prices tourist/first class , location of
train station in BA , and if there is a web site for booking online ) .
Any help will be much appreciated.

Thanks Michael

There is a service between Buenos Aires and Mar del Plata. Im not an experienced train traveller but here is what Ive been able to dig up:

http://www.sateliteferroviario.com.ar/horarios/mardelplata.htm

Sorry, it seems like the information is only available in Spanish. As far as I can tell, no online booking is possible and the tickets must be purchased in person.

It seems like they have 4 different classes of service, the premium seems to be Super Pullman and costs AR$55 (one way).

Please note not all classes of service are available every day, the Super Pullmann is only available from Bs. Aires on Saturdays, returning on Sundays from Mar del Plata.

On a side note, there are also services to Tandil and Pinamar, available, see links:

http://www.sateliteferroviario.com.ar/horarios/mardelplata.htm#Pinamar

http://www.sateliteferroviario.com.ar/horarios/mardelplata.htm#Tandil

On a side note, there are also services to Tandil and Pinamar, available, see links:

http://www.sateliteferroviario.com.ar/horarios/mardelplata.htm#Pinamar

http://www.sateliteferroviario.com.ar/horarios/mardelplata.htm#Tandil

Thank you very much Gaucho100. You are really going out of your way to
find the info for me. You are a good ambassador for Argentina .
Now to the subject ; I understand enough spanish to understand the link
you gave ( and all the links from that one ). I'll make my reservation
on the phone when I arrive to BA on the 31st of JAN.( before going to
IGR for 3 days - 2nd to 5th Feb. ).

Thanks again
Michael

Your very welcome... have a great trip!!

deleted.

Just as an update, train services to the coastal areas have been having more than their usual share of issues lately, perhaps they are not the best option at this time. I suggest considering flying or taking a bus.