Can I do a chapter 13 bankruptcy on only secured debts?

Your question as stated doesn't really make any sense.  Chapter 13 allows for a repayment of your debts.  The percentage to be repaid depends on your budget, the value of your assets and other considerations.  Unsecured creditors can be paid anywhere from 0-100% depending on the above.   Secured debts must always be paid in full unless you are "stripping down" pursuant to 11 USC 506 when the value of the collateral is less than the amount owed to the creditor. You can also use a Chapter 13 to catch up on past due amounts on secured debts. You need to have a consultation with a bankruptcy attorney in your area to get a fuller answer. Mark Markus has been practicing exclusively bankruptcy law in California since 1991.  He is a Certified Specialist in Bankruptcy Law by the State Bar of California Board of Legal Specialization,  AV-Rated by martindale.com, and A+ rated by the Better Business Bureau.