The U.S. Citizenship and Immigration Services does publish a Spanish-language version of the Employment Eligibility Verification Form I-9 (www.uscis.gov/files/form/I-9Span.pdf). But as noted at the LEAP Conference in April by Gary Perl, a partner at Fragomen Del Ray in San Diego, “It’s not up to you to use that version … Employers can only use the Spanish form if their employees are in Puerto Rico.”
If you’re not in Puerto Rico, you can still use the Spanish version to help employees understand the form. But the English version must be the one you complete for all workers.