Rubuta ci gaba don wannan sakin layi - Gamarra ya bayyana ga tawagar 'yan wasan Paraguay sau 110, ya zira kwallaye 12, daga 1993 zuwa 2006, yana wakiltar tawagar a manyan wasanni 10 kuma ya jagoranci tawagar a lokacin karshen aikinsa. Shi ne na biyu mafi yawan 'yan wasan da aka buga a tawagar kasa, wanda Paulo da Silva ya karya a shekarar 2013. Gamarra ya bayyana ga Paraguay a gasar cin kofin duniya uku na FIFA (1998, 2002 da 2006), gasar cin kofin Copa América biyar (1993, 1995, 1997, 1999 da 2004).
), kuma sau biyu a Wasannin Olympics na bazara (1992 da 2004, tare da Paraguay da ke da lambar azurfa a na biyun). An zabi Gamarra a matsayin dan wasan kwallon kafa na Paraguay na shekara a shekarar 1997 da 1998, kuma an kuma hada shi a cikin 1998 FIFA World Cup Team of the Tournament.